Loved the budget rebuild...your comments are spot on...thanks for being direct...after working with my uncles, brother and father in their Garages, I found out what you mean the hard way...customers have no idea what the time and expense, not to mention knuckle busting and undoing Mickey Mousing, is...In over my 40 years experience, I have never found anything that goes, exactly by those "manuals" ...maybe those Detroit boys on the new stuff but not on the everyday rides...sincerely, Rev. Ken
Schrodingers Box hey mate, just got a quick question is it possible for my upstream o2 sensor to read 1.513 volts constantly? from what I've learned they should only be between .2 and .8 of a volt, my car is overfueling but there is no codes showing when engine is idling at running temp the voltage on the o2 sensor stays the same always and my long term fuel trim is stuck at 3.1% no matter what I do like revving the engine or removing vac pipes. I am a tech but I'm HGV and have never had anything to do with o2 sensors or fuel trim and I don't just want to buy a sensor I'd rather be 100%. Thanks and epic channel my friend.
The UnrulyUA-camr It is not possible. You should probably read at the O2 sensor directly and see if it is oscillating and my bet is you have some issue with the Bias voltage and you won't see 12V bias. But the sensor itself won't read 1.5V. The other possibility is maybe you have an A/F sensor instead of O2 sensor.
Another excellent and informative video based on logic and not just "common wisdom." Just finished your budget rebuild videos and learned a lot before diving into an old pickup motor I've been looking forward to rebuilding. One thing I might suggest you keep in mind though. Some of us don't look upon the time spent turning wrenches or measuring tolerances as drudgery to be farmed out to a professional mechanic/shop. For me, that's the fun part. Look forward to more of your good work.
RITE!!!I SOMETIMES LOOK 4 ANY REASON TO DISASEMBLE MY CAR OR THE OLD LADIE'S CAR JUST 4 FUN NOT 2 MENTION THE LAWNMOWER,THE RIDING MOWER'GO CART,HECK,ANYTHING WITH WHEELS & A MOTOR. OR ELECTRONICS.AS A CHILD
Good to see my favorite 2%'er on UA-cam back. Yeah the old Chevy truck I sold the gauge showed no oil pressure. The guy who bought it put an oil pump in but didn't help much because he did not replace bearings.
Awesome video. Short, sweet, to the point, and not lacking in any useful info. Thanks to you, I've learned a lot on diagnostics, and as a backyard mechanic, people think I'm good at what I do because of it. And you've really left me shaking my head at all the parts changers I know, whom excitedly tell me about their automotive adventures. Morons.
Great vid Matt. You quickly and irrefutably concluded that the only real fix at this point was a rebuild or swap. Not sure why some of the folks commenting don't seem to get that. To the viewers, before commenting on this video to offer "help", please consider not suggesting that the oil pump was the culprit, and know that the oil pressure readings Matt got were absolutely NOT within spec. The only thing worse than being stupid is to pass along stupid advice. If you disagree, please watch this vid again.
could not have said it better myself!! Indeed the whole point of the channel is to be a safe haven from the stupid advice out there. That’s what my whole motivation was to create the channel- because of my frustration with all the chaff out there. Thanks for your support!!!
thank you i learned more from your vids than ive done in the past 10 years i always asked how stuff works and never got an reply from the men i was working with i now know they did not have a clue what they were doing and even thou they went for all the training the world wide company had to over and i was left behind to make the dow they stil dont have a clue thanx michael from sa
Very helpful video as always Matt. I've said it before and will say it again - you put a lot of professional technicians to shame. This channel is my second favourite - your paid channel takes top honours for me.
Thanks man!!! I believe based on the comments on this video I need to do a D&U on oil pressure. Most people here have the misconceptions that the oil pump creates pressure, the oil gauge indicates pressure, and that oil pressure should be 4PSI at idle. All of these are false.
Well u did 2 great things here you fixed the rad, so he can now use it and u also confirmed an issue he has with the engine. It's not good to hear that but you were not aware of it I am sure if you had been the outcome would most likely been the same fix the radiator and leave the other issue as the only thing that can truly fix it is an expensive rebuild. Great and truly thorough job love you diagnose vids.
Those are cool vehicles, I have been working on one of these this week that my sister owns, it is a 5.9 L with 9:1 compression and wow it has lots of power almost like a police interceptor engine
Matt, I got to admit, I don't go to the best garage, seeing how they messed up my coolant lines when changing the accessory belts... I also had them change the oil and filter. Everything was fine before. But fairly soon after the change, my oil pressure gauge started "swinging" beween 0 and max, depending on rpm and temp. Have been driving a something like 1000-2000 miles with it since. When it start having a low below 30, I just put in half a liter or a liter of oil. The engine starts and runs, has power, even on german autobahn (100 mph+). But I'm not sure if I'm destroying the engine for good, or if it's fixable. Here on youtube are a lot of video's with the same exact symptom, but no one shares the diagnosis. So my guess is, it's very very bad news.
Great video. As an aspiring 2 percenter (well I guess I am one because I never parts change unless I consider it something I wanna change anyways) I wanted to watch this vid both for entertainment and to see what may have flown right over my head. My Jeep 4.0 seems to have odd oil pressure but it may be fine or it may be a sensor or needs an oil change or a combination of both. After all it is a little low on the dipstick so that may be it. It having 255K and oil leaks scares me but maybe I’ll end up being said dipstick.
Change the oil,and put in 50 weight. Retest the pressure. If the engine is that worn but makes good power and isn't burning oil, run it till it dies. The knocking is most likely in the lifters or chain tensioner. If the rods are knocking, they won't stop when the pressure is normal. I seem to remember there is an oil pressure regulator at the pump.
Well Identifix specifications for this engine are At idle, it should be 6 PSI and it is at 20. At 6000 RPM. You don't think that the drop on pressure at the gauge was caused by the bad sensor?
At what TEMPERATURE?? No one seems to consider the most ciritical parameter despite my pointing this out in the video. How can it be a bad sensor? The evidence is scientifically irrefutable it could be the sensor.
Hi. Nice vid and very clear explanation. Im here because i owe an 15' nissan rogue and it show the warning text low oil.pressure. 2 days ago. Today i check and there is a spot of grease on the driveway. I will bring a mechanich and i hope i dont need a new engine.
it depends how it is designed. some potentiometers increase resistance with a positive change, some decrease resistance with positive change. There are also other systems that compare to a fixed reference voltage. so it’s not so much if it reads higher or lower- it’s the absolute value of the difference that matters.
Great video! Thanks for making it. My question is if someone can't afford to replace the engine, would you recommend to go through the hassle of replacing the oil pump and rod bearing? I have the same problem and was told that replacing those two parts is the alternative cost effective solution. Any input will be greatly appreciated. This is my work truck and if it dies I will not have a job. Please help.
to be honest, the proposed solution sounds like a bottom end rebuild which is roughly the same cost/work as the budget rebuild he did here ua-cam.com/video/R1qBJ8ZeOUA/v-deo.html
How many miles on this engine? What does the odometer read? Certainly it wouldn't hurt to drop the oil pan, check the screen for clogging and pump tolerances. That metal could be coming from anywhere like a worn camshaft lobe for example. Very difficult in this video to see the metal fillings/color in the oil sample shown. The oil does look super thick and dirty. I bet there is tons of sludge inside due to lack of regular maintenance. After you changed the oil and filter what symptoms were noted?
Ozzstar you hit it right on the dot my friend. Jumping straight to an engine replacement is being a bad mechanic. Change the oil sending unit, and run some cleaner with the oil change etc. This would give a better picture.
My Crown Vic oil pressure never varied...it looked like an oil pressure gauge on the dash but turns out it is actually an oil pressure indicator. If you have at least 5 lbs of oil pressure then the needle goes half way up. Very deceptive of Ford.
I was thinking of testing the sensor different. It's a variable resistor like a coolant temp sensor. short out that 5 volts and watch the gauge. or just unplug the sensor and see where the gauge is at w/ 5 v sig. alternative readings if the computer doesn't some how shut down the circuit. Tests the entire circuit. Your correct the gauge and wiring is good as the gauge is reading the same as the pressure sensor. But just checking the sensors ohms with varying pressure doesn't 100% rule out wiring and gauge.
Great to see you making videos again. Not so sure on this diagnosis, but I could not hear the rod knock. What is the specification for engine oil pressure at idle for the 2000 Dodge Durango 5.2L? On my V6 Toyota Camry it is 4.3 psi or more and at 3,000 rpm it is 36 to 78 psi. Also, on the oil diagnosis, I would use Blackstone Labs before recommending an engine rebuild and pay $28 for their engine oil analysis.
This was a cold startup with the gauge failure activation being at 7PSI for this vehicle and we saw activation twice at end of IAC flare. There is no argument- this is legitimate low oil pressure.
How many miles on that engine? These engines are known for oil sludge buildup if oil is not changed regularly. Is it possible that the oil pick up screen is clogged with oil sludge?
in my 73 charger 318 i had low oil pressure after about driving 20-30 mins it would be at 40 then go to 20 so i took the oil pan off and saw the oil pickup was full of leaves and old silicone from previous owners while i was down there i rotated the engine looking to see my rod bearing were any good surprisingly they were still very tight and no metal material it makes the oil look kinda grey even when you showed your sample to us it looked grey and a bit like glitter normal old looks like its black or very brown right afterwards i put it all back together and it now stays a solid 60 psi on the oil gauge even after 1-2 hours of driving
it was not too bad i bought a 440 a guy said ran and it was full of acorns lol he had run it the day before he said and i believed him because it was on a wooden run stand lol
What about the oil grade was wrong? My 2005 Suzuki Forenza start this problem after mechanic changed oil and and replaced timing belt Also started a knocking valve.
Hey, you missed out on the EricTheCarGuy 2016 meetup. ScannerDanner was there, and you're favorite mechanic on youtube was also there; Eric O. from South Main. It would have been a blast to see you two guys hit it off.😆
Unfortunately we were unable to meet up. I have actually been to Pittsburgh 4 Times this year (my corporate HQ is there) but I haven't even had a chance to visit downtown. my schedule is so packed when I travel I wouldn't even know what city I am in if they didn't tell me where I was going !!!
1996 Chevy Camaro Z28 my oil pressure gauge goes to zero after a while. I replaced the sending unit and nothing. I check the oil and it looks fine and I don’t hear any knocking and it’s doesn’t overheat and the engine sounds ok. I was told it could be the bearing? What other possibilities it could be? Thanks for any information
I wonder why you don't even mention the possibility of a worn oil pump? Sure it could be the big ends (indicated by the engine knock you mentioned). But surely after the pressure switch, next thing you'd check the oil pump - before doing a major bottom end rebuild?
because the oil pump does not create pressure. we can see the flow is sufficient but insufficient pressure is present. that cannot be from a bad oil pump.
So I just bought a 98 dodge ram 1500 and was told the same thing that its a sending unit but mine will sit at like 38psi then drop to zero for a minute then go back up to 38 then drop its like 30 sec intervals
good troubleshooting but would have been more helpful if indicated what pins on harness and sending unit meter connected to. as always though, helpful videos
I suspect it was replaced by a typcial non-diagnosing hack that was hoping it was just a bad oil pressure switch. Incidentally this car did finally blow up this summer when the rod knock became so bad the timing was off enough the car wouldn't drive. Eventually the guy threw a rod because he had to floor it to even make it go.
matt Im in the UK ,but I suppose probably not much different where you are regards engine design ,but could it not possible there is a problem with the pressure relief valve, only a thought as you are sometimes getting pressure.regards joe
Hi, glad you are back. When will you do a video on radiator fan running for too long and stop for too short with no apparent reason. What would be the issue that makes them behave this way ?
I just installed some Boush Mechanical gauges to my 283 Chevy Sm Block, it has 37 pounds of pressure at start up at 1500 Rpm, Book say should be 38 Pounds at 1500 Rpm. But after warm up, it drops to like 20 pounds?
Some of the Chryslers of that era have "fake" oil pressure gauges. The dash gauge either reads in the normal range or it reads zero but never in between. That sending unit appeared to be variable, and that's what the wiring diagram shows for that 2-wire sending unit, but the dash gauge was either zero or 30 but never in between. Kind of strange. It's too bad there are dishonest people that would rip someone off like that. Sad. That sending unit looked pretty clean like maybe someone had replaced it and realized there was a bigger problem and dumped it on someone else.
Hi dear teacher, I have 99 jeep cherokee with low oil pressure (check gauge light) with new 3 wire pressure sensor. I checked the 5v ref. and the ground and they are OK. I check the continuity of all 3 wires using the wiring diagram and they are Ok. I extended separate signal wire from the sensor signal to the control but didnot fix the problem. The sensor signal voltage is fixed at 0.17 V with plugged connector. I tried to get 5V ref. from the ECT sensor through my test lamp and put it into my unplugged connector signal and also there no respose. If the oil pressure is ok, is there any possible causes except bad pcm?? Im I a good student?
Yes you are a good student. You did very well. You must have the connector unplugged to see the 5V signal. Measure with it unplugged and if you find 5V then your next step is to use a gauge to measure the actual oil pressure mechanically. If however you don’t have 5V, then there is some type of wiring issue. It should be there.
@@SchrodingersBox I checked the 5V and the 3 wires and the actual oil pressure and they are all OK. Thats why im sending you. So, is it now the PCM or still there is something to check?
@@SchrodingersBox many many thanks my perfect teacher. Finally it was a bad new pressure sensor. I replaced the new sensor with another new one and it works great. Many thanks again
@@SchrodingersBox but how can I test the 3 pin pressure sensor. Is there a prober method to bench test this 3 pin sensor. Which resistance should I measure?!
I have a 2012 ram 1500 5.7 hemi. Oil pressure fluctuation from normal to low with warning light. Slight temp increase. Stuck 500 miles from. Home need ideas
The old "bad oil pressure sending unit" excuse is never a good sign. I recall taking an old truck for a test drive and it was smoking like crazy under the hood. He told me it was just the valve cover leaking... yeah, sure.
On my kubota generator diesel engine, if my oil pressure goes below 10 psi it shuts off automatically. Also if the engine gets too hot over 240F it shuts of too prevent overheating. I dont know why they dont have this on gas engines.
Yeah it should be a default that on overtemp or low oil pressure the engine shuts down. It's going to shut down anyway when it blows so why not save it!
the specification of the oil pressure at the specific vehicle is 6psi at idle and 30-80psi at 3000 RPM with engine at operating temperature. you might double check that sensor .
Absolutely incorrect. First off the evidence is irrefutable that this is NOT a sensor issue as evidenced by the obvious symptoms demonstrated. Second, the curb idle at cold startup should easily be 40psi. Third, as evidenced twice in the video, and as documented in service manual, the gauge failure trigger is 7PSI. We in fact saw this actuation twice as soon as the IAC stablization occured. Electrical and flow confirmations were equally irrefutable. To say this could even possibly be a sensor issue is absolutely ludicrous.
david cisneros I am saying use logic and reason. Look at the evidence presented. It is IMPOSSIBLE based on simple, basic, remedial understanding of fundamental operational concepts that the problem with this car could even theoretically be a bad sending unit. You will need to explain the symptomatic etiology otherwise you would just look foolish saying what is obviously contraindicated by multiple examples.
what I'm saying is base on the oil pressure readings been at 10psi and with a malfunction gauge at the dashboard you might have a bad sending unit and not oil pump cording to all data . I'm not saying you don't have bad engine do to other mechanical issue.
What you are saying is necessarily contradictory. An engine with the evidenced bearing damage and knock MUST have excessively low oil pressure. This is basic fundamental fluid mechanics, my friend. So even if the sending unit was bad, which it is definitely not as was irrefutibly evidenced in the video, it would be irrelevant anyway. Ignoring evidence you don't understand makes for an illigical thought process, albeit simplified.
my Ford Explorer is doing the same thing with the m Dash on my oil it seem that there's no oil and there is so mine's a little different my truck does not have a knocking sound to it at all and what would that be
Then I would IMMEDIATELY diagnose the issue. If it's actual low pressure you may be able to intervene without catastrophic damage and get by with just bearing replacement.
what causes this. my wife's car just died and this is what it was doing. I thought the sensor was bad because I new the oil was full because I just changed it and it was running fine.
HillbillyMatt ExtremeDIY When the engine bearings are worn the space the oil passes through is enlarged, which of course exponentially reduces the pressure.
Schrodingers Box aha. that makes a ton of sense. I am so hooked on your channel. as you may be able to tell by my name I enjoy pushing conventional rules of DIY. as you probably know when you are rengineering the conventional you have to do all of the homework. I appreciate it when I find a good source of detailed knowledge like your channel. you are very thorough and you make it understandable. thank you. I was trying to find the video that you refernced in your extreme budget engine rebuild video, in which you discuss why rod nock is an absolute engine replacement/rebuild. what is the title? I tried searching "schrodingers box rod knock" to no avail.
HillbillyMatt ExtremeDIY Welcome to the channel! Try searching the channel itself. It is under the "about" tab on the main channel page if I remember- there is an option "search channel" as opposed to searching all of UA-cam.
Looking for advice, 02 altima with fuel trims at negative 15 to 20 %, code 0300, O2 V at 3 to 6 V. and long crank start after warming. fuel pressure good, compression good, does not stall. unplugged vacuum line and trims improve but o2 voltage remains at same levels. ??
the STFT I mentioned is at idle, with LTFT at neg 10%, under, load during take off it goes up anywhere from 0 to + 5 % at best, once settled STFT goes back to as low as negative 18%, unfor did not check LTFT,
well at this time I have no tools to test injectors, (I might be jumping to conclussion)I stumbled upon your videos not long ago! been reviewing the diagnostic series, I might need to test fuel pressure since I only saw pressure while cranking, it had no pressure when switch at on position!
in my case the problem (very persistent oil pressure warning on idle sometimes with miss fire on all cylinders but not always) was dirty vvt adjuster/magnet! Litle bit of parts cleaner sprayed in each hole and problem is solved!!!
Totally my preference too! But on some models, dropping the pan is very time consuming. The nice thing about this method is there is no need to drop the pan. We can confirm the issue without even getting under the car.
The knock and the chromium visibly present (indication of ring wear, exacerbated by loose rod bearings which allow the pistons to "slap" around and wear out the rings) in the oil were already indicative that the engine is worn out.
I have a 98 chevy 5.7. At idle warm my preasure is a little under 40 on gauge and of course when hit throttle it goes up but never drops lower then like 38. Know it's just a work truck and never goes on high way and I dnt plan to keep it much longer but I do need it to perform for the next couple months. Should I be worried? Done oil change distributor plug wires could almost all sensors on engine I just rebuilt the front end like stearing components. The lower intake needs to be done the engine only has 150k on it should I RIP the engine out and find a used one with lower mileage and before install change intake gaskets and oil pan gasket and run it if I plan to keep it or just run it till shes dead. I have a spare engine in a parts truck I bought that runs but has 230k on it idk if o should just pull that do the same same lower intake and oil pan gasket possibly spider injectors and slap her in it's just the mileage it has on it and it's a old plow truck so I'm sure that engine did alot of idling. Just dnt know what rt I should take junk yard engine or one in parts truck that has 230k or just run mine with low oil pressure. Or is 38psi at idle ok?
Is it possible to make my 2000 Golf 4 shoot flames or backfire, if i rev up my engine, then turn off the ignition and press a button connected to my fuel injectors and turn on my ignition again to make it shoot flames? Just like old cars with carburetor
Average 'good' pressure would be (and this is for a well used engine that is still in good shape) 10PSI for ever 1k RPM. That's a bit of a minimum pressure. Combine this with the pressure dropping below 10PSI which it did a few times-and the bearing grit in the oil. The engine is done. Needs at least a basic bearing set-which while you're in there, do the job right.
I see someone just mentioned "6psi" for oil pressure being good at idle. Me thinks I'll stick with the 10psi at 1k. If it's that low at idle, and you tromp on the gas? It will be one hell of an oil starvation problem. (It takes a tiny bit of time before the increase in RPM equals increase in oil pressure. Not a lot of time mind you! But enough it could accelerate the damage already done)
Tedybear315 well the engine i was talking about (mercedes m103) shows 6-8psi at 600rpm idle with a warm engine. as soon as you hit about 1500rpm the oil pressure builds up to about 50psi. the instruction manual says that this is how its meant to be with this engine.
Not on a cold startup- that would be for fully operating temp andf even then, anyone buying a car where a dummy gauge like the one on this car indicates 4 would be foolish.
He decided to drive it until he can hopefully save for another vehicle. I agreed to go with him to ensure he gets a much more reliable vehicle when he is ready.
He definitely will use your expertise when buying another vehicle. It's a shame this one will end up in the scrappy! I hate to see cars die! Thanks mate!
dang just did engine and another mec told to me it's leaking on oil sensor. why that should of been replaced with engine. ahh. and the power steering pressure line leaking too and 02 sensor, engine light on. ahh . Gosh when I got it back from mec the oil showed none. I put lucas and oil. took it to another shop they said add one quart more oil said maybe dip stick is maybe wrong one.
Hi, i rebuild a gm grand am 1999 2.4l ld9, troubleshooting is i fill up the engine oil full of the gadge, oil dipstik ok but when i start the engine few min and stop, i take a look on the dipstik again and oil is very low, do you have an idea, where the oil goes, no leak everyting seal on spec. Thank’s. Ben
it won’t be a compression problem. possibly a seal problem. anyway when you see the fuel trim show a proportionately rich curve compared to load, that obviously would be indication on where to suspect the issue.
Schrodingers Box yes i have to check more specific fact, i am going to take a look and see the troubleshooting, when is done i reply to you and see what i found thx a lot. Ben
Would a higher volume oil pump be a budget hack to extend the life of that beater? More volume would force up pressure right. Don't judge I just woke up.
I have a lexus IS350 2007 with low pump pressure, i have bought 3 different oil pumps and no change, the car starts fine, but the oil pump pressure is very low. Pls what do you advice?
Why are you replacing the oil pumps- what is your evidence the pump is the issue? What is the voltage and amperage at the pressure sensor vs actual mechanical pressure?
No need- just find the source of noise and confirm through visual confirmation. There is no skill in diagnosing noise- you just have to tear into it. See my other engine noise videos and it's very easy to diagnose even with no skill or experience.
Well the only issue is that I live in an apartment complex not a house. They don't like people doing much of anything on cars here and I have limited tools. I should say I would really just like you to look at it since I am going to have no choice but to take it to someone and have the most confidence in you rather than typical part changing shops. Its an 05 neon standard trans and it sounds like gears want to fall out when I'm coasting in neutral.
The moral of the story is that you should *never* believe what the seller says 100%. Always take what they say with a pinch of salt and use your common sense and judgement. Or even use it as a bargaining point to get a better deal as you are taking a risk. If in any doubt and you are not willing to risk it (you can't fix it cheaply yourself, for example), walk away. If it really was just a pressure sender unit, the seller, in theory, should have had it fixed as it's a cheap and easy repair - why would he have an obvious fault that would mean less chance of selling the vehicle, and getting a lower price for it?
Rebuild? Gee.. well, I think if owner is on a budget, a junkyard engine might work, find a rebuild-able on craigslist or eBay, find a shop willing to sell a donor engine, other options.
HELP! I have a 2008 2.2 litre Ford transit van. The oil light is on. I have carried out an oil pressure test and get in excess of 60 psi. I have installed a new pressure sensor and the oil light is still on. It goes off if I pull the sensor wire off so I don't think it is the wiring. Any ideas? I am stumped at the moment! The engine sounds as sweet as a nut and the oil level is ok.....
@@SchrodingersBox I will take a measurement just as soon as it is warm enough to go outside. We are having an extreme cold spell here on the Isle of Man. Thanks for responding, it is much appreciated.
@@SchrodingersBox I have just measured the reference voltage on the wire that connects onto the oil switch ( with it removed from the oil switch) and with the engine running. It is a fairly steady 14 volts. As soon as I reconnect it to the oil switch the oil pressure light comes back on.
@@SchrodingersBox Is there a difference between a pressure sensor and a pressure switch? I am under the impression that the oil pressure switch has positive supply voltage connected to it. With the engine off and therefore no oil pressure the pressure switch allows a connection to chassis earth and the oil light therefore comes on. When the engine starts and the oil pressure is present, then the oil switch breaks the connection with chassis earth to put the oil light off. The battery system on my UK vehicle is nominally 12v. I am guessing it rises to 13 or 14 volts when the alternator is charging the battery. I must admit, I was not expecting 14 volts. The vehicle manual, that I have does not give any information on this particular circuit and oil switch.
That test on the pressure sensor only showed it was alive, Without knowing what pressure gives what voltage it is hard to say that it is working correctly. I do agree that the Engine isn't long for this world though. :(
@@jessemichel7073 the most common cause of low oil pressure is worn bearings, those are lubricated internally by oil passages. If they get sloppy too much oil flows and you lose oil pressure. The sound of the engine combined with the metal particles in the oil leads to the conclusion of the engine being shot.
Hi matt, I am having a similar issue. The oil in the cylinder head is very less when the engine is running. I hear loud rocker arm noise. Could this be a failing oil pump? I changed the oil filter but no changes. No particles in the oil. Could it be a blocked oil gallery ?
if we came from other side, Bad oil bump can cause inefficient lubrication and bearings is going to wear out. Pressure will fail down with time, am I right? because this is what happened to my Nissan Z I guess.
Low oil pressure is usually or almost always a worn motor and the bearing clearances are way out. One way to confirm is to check the oil for metal as he did.
Curious what drop-light you are using...Looks to be a LED type... The incandescent one I use with metal cover is hot enough to cook a steak on it and sometimes touches my ear under the car...
Hi, love your show have a quick question I have a 350 Chevy small block I have a autometer gauge hooked up to it when I started up my oil pressure is about 30 when it's warm what about 20 minutes it goes down to about 20 is that normal
Hell ya, thanks for posting man!!!! missed ya . Half the time if you grab a junkyard v8 with decent miles on it, it's cheaper than a full blown rebuild after u buy the kit and all of the nicknacks. Unless you just go for bare bones what u need to get by or whatever. Looking forward to seeing the budget rebuild if it is in the young mans budget. P.S. i heard that lieing is bad for your teeth, the previous owner needs a pop in the mouth to prove that theory.
Lol agreed on everything! I have done many dozens of salvaged yard swaps- it's how I started in this hobby in fact. I used to swap an engine for no more than a $500 investment total for everything including new gaskets and fluids. But I no longer do major work now.
I have a 2006 chevy Silverado with a 4.8 and 119,000 miles, it runs good but the oil pressure hangs around 30-35 when warmed up. What could I do to get it back up to 40 psi at idle? @@SchrodingersBox
Are you going to try and rebuild the motor or are you guys going to find another motor? If you rebuild this motor are you going to continue the budget rebuild series from the ford? Thanks for doing these video's, they are really helpful.
How are you measuring oil pressure? It’s hard to imagine you have good pressure and no oil to top end. And if you had a clog or something the pressure would be really high. Are you measuring using a mechanical gauge at the oil pressure sensor port?
@@SchrodingersBox Thank you for reply!! Used a high quality guage to read pressure at sensor port; if it was blocked oil gallery or turned bearing? Scared but need to know; car has 3.8 supercharged with 230km.
@@SchrodingersBox I removed valve covers and let engine run for about 90 sec; oil pressure was 50psi but no oil to all lifters. Then removed intake and lifters looked ok, also no oil in the valley. Oil pickup screen and oil pan were pretty clean
@@SchrodingersBox The car is 2006 grand prix with supercharged 3.8l, series II. Is it possible to manually pump oil through the motor to c if it has a clog?
If he is strapped for money can you do a junk yard engine swap for him. It might save him a few hundred bucks. Just my 2 cents lol. Your videos are great!!
several years ago I did tons of major repairs like that but nowadays due to time constraints I no longer do rebuilds or swaps. He's on his own unfortunately.
Yikes! Sorry to hear that! Too bad you went through all the work of the radiator only to find out the engine is shot. I feel bad for you, he shoulda said something about the low pressure and or knock first.
Loved the budget rebuild...your comments are spot on...thanks for being direct...after working with my uncles, brother and father in their Garages, I found out what you mean the hard way...customers have no idea what the time and expense, not to mention knuckle busting and undoing Mickey Mousing, is...In over my 40 years experience, I have never found anything that goes, exactly by those "manuals" ...maybe those Detroit boys on the new stuff but not on the everyday rides...sincerely, Rev. Ken
Glad you're back with another video. One of the best tech/mech on UA-cam
Thanks OZ! I try to produce content when I can but it's tough these days!!
Totally understand. I'm sure all your die hard fans/ subscribers truly appreciate your time and knowledge that you give us in every video you upload.
Oz Mechanics Can't tell you how much I appreciate you guys. I really do!! Thanks Oz! It's great to hear from you!
Schrodingers Box hey mate, just got a quick question is it possible for my upstream o2 sensor to read 1.513 volts constantly? from what I've learned they should only be between .2 and .8 of a volt, my car is overfueling but there is no codes showing when engine is idling at running temp the voltage on the o2 sensor stays the same always and my long term fuel trim is stuck at 3.1% no matter what I do like revving the engine or removing vac pipes. I am a tech but I'm HGV and have never had anything to do with o2 sensors or fuel trim and I don't just want to buy a sensor I'd rather be 100%. Thanks and epic channel my friend.
The UnrulyUA-camr It is not possible. You should probably read at the O2 sensor directly and see if it is oscillating and my bet is you have some issue with the Bias voltage and you won't see 12V bias. But the sensor itself won't read 1.5V.
The other possibility is maybe you have an A/F sensor instead of O2 sensor.
Another excellent and informative video based on logic and not just "common wisdom." Just finished your budget rebuild videos and learned a lot before diving into an old pickup motor I've been looking forward to rebuilding. One thing I might suggest you keep in mind though. Some of us don't look upon the time spent turning wrenches or measuring tolerances as drudgery to be farmed out to a professional mechanic/shop. For me, that's the fun part. Look forward to more of your good work.
RITE!!!I SOMETIMES LOOK 4 ANY REASON TO DISASEMBLE MY CAR OR THE OLD LADIE'S CAR JUST 4 FUN NOT 2 MENTION THE LAWNMOWER,THE RIDING MOWER'GO CART,HECK,ANYTHING WITH WHEELS & A MOTOR. OR ELECTRONICS.AS A CHILD
Good to see my favorite 2%'er on UA-cam back. Yeah the old Chevy truck I sold the gauge showed no oil pressure. The guy who bought it put an oil pump in but didn't help much because he did not replace bearings.
Awesome video. Short, sweet, to the point, and not lacking in any useful info. Thanks to you, I've learned a lot on diagnostics, and as a backyard mechanic, people think I'm good at what I do because of it. And you've really left me shaking my head at all the parts changers I know, whom excitedly tell me about their automotive adventures. Morons.
Great vid Matt. You quickly and irrefutably concluded that the only real fix at this point was a rebuild or swap. Not sure why some of the folks commenting don't seem to get that. To the viewers, before commenting on this video to offer "help", please consider not suggesting that the oil pump was the culprit, and know that the oil pressure readings Matt got were absolutely NOT within spec. The only thing worse than being stupid is to pass along stupid advice. If you disagree, please watch this vid again.
could not have said it better myself!! Indeed the whole point of the channel is to be a safe haven from the stupid advice out there. That’s what my whole motivation was to create the channel- because of my frustration with all the chaff out there.
Thanks for your support!!!
thank you i learned more from your vids than ive done in the past 10 years i always asked how stuff works and never got an reply from the men i was working with i now know they did not have a clue what they were doing and even thou they went for all the training the world wide company had to over and i was left behind to make the dow they stil dont have a clue thanx michael from sa
Thank you for all the info, keep making these videos because you're helping alot of tech/mechs.
Very helpful video as always Matt. I've said it before and will say it again - you put a lot of professional technicians to shame. This channel is my second favourite - your paid channel takes top honours for me.
Thanks man!!! I believe based on the comments on this video I need to do a D&U on oil pressure. Most people here have the misconceptions that the oil pump creates pressure, the oil gauge indicates pressure, and that oil pressure should be 4PSI at idle. All of these are false.
Well u did 2 great things here you fixed the rad, so he can now use it and u also confirmed an issue he has with the engine. It's not good to hear that but you were not aware of it I am sure if you had been the outcome would most likely been the same fix the radiator and leave the other issue as the only thing that can truly fix it is an expensive rebuild. Great and truly thorough job love you diagnose vids.
I'm so glad that you are doing this for free, nice
You should see my pay channel then!
Those are cool vehicles, I have been working on one of these this week that my sister owns, it is a 5.9 L with 9:1 compression and wow it has lots of power almost like a police interceptor engine
glad to see you back
Knock, knock knockin on heavens door.
ROTFLMAO!!! Nice I have to remember that one!!!
Tom OConnor: Mama put my 5.2 in the ground... I can't use it anymore
Lmao just made me sing the song
Hello Matt
Nice to see you back
Matt, I got to admit, I don't go to the best garage, seeing how they messed up my coolant lines when changing the accessory belts... I also had them change the oil and filter. Everything was fine before. But fairly soon after the change, my oil pressure gauge started "swinging" beween 0 and max, depending on rpm and temp. Have been driving a something like 1000-2000 miles with it since. When it start having a low below 30, I just put in half a liter or a liter of oil. The engine starts and runs, has power, even on german autobahn (100 mph+). But I'm not sure if I'm destroying the engine for good, or if it's fixable. Here on youtube are a lot of video's with the same exact symptom, but no one shares the diagnosis. So my guess is, it's very very bad news.
oil pressure sensor/sender.
Great video. As an aspiring 2 percenter (well I guess I am one because I never parts change unless I consider it something I wanna change anyways) I wanted to watch this vid both for entertainment and to see what may have flown right over my head. My Jeep 4.0 seems to have odd oil pressure but it may be fine or it may be a sensor or needs an oil change or a combination of both. After all it is a little low on the dipstick so that may be it. It having 255K and oil leaks scares me but maybe I’ll end up being said dipstick.
Change the oil,and put in 50 weight. Retest the pressure. If the engine is that worn but makes good power and isn't burning oil, run it till it dies. The knocking is most likely in the lifters or chain tensioner. If the rods are knocking, they won't stop when the pressure is normal.
I seem to remember there is an oil pressure regulator at the pump.
Yes I suggested 50W but ultimately this engine is doomed and at best it is unreliable
Well Identifix specifications for this engine are At idle, it should be 6 PSI and it is at 20. At 6000 RPM.
You don't think that the drop on pressure at the gauge was caused by the bad sensor?
At what TEMPERATURE?? No one seems to consider the most ciritical parameter despite my pointing this out in the video.
How can it be a bad sensor? The evidence is scientifically irrefutable it could be the sensor.
You also have to check the oil pickup tube connection to the engine block.
not with low pressure that varies with load. No, the pickup is clearly operational in this case.
Hi. Nice vid and very clear explanation. Im here because i owe an 15' nissan rogue and it show the warning text low oil.pressure. 2 days ago. Today i check and there is a spot of grease on the driveway. I will bring a mechanich and i hope i dont need a new engine.
Explain to me why the reading on your multimeter dropped when you increased the air pressure into the sending unit please
Because it is a potentiometer- it changes resistance with movement of the sweep. Lower resistance lowers voltage (ohms law).
It seems like (as a pressure gauge) it should read higher with more air pressure?
it depends how it is designed. some potentiometers increase resistance with a positive change, some decrease resistance with positive change. There are also other systems that compare to a fixed reference voltage. so it’s not so much if it reads higher or lower- it’s the absolute value of the difference that matters.
Great video! Thanks for making it. My question is if someone can't afford to replace the engine, would you recommend to go through the hassle of replacing the oil pump and rod bearing? I have the same problem and was told that replacing those two parts is the alternative cost effective solution.
Any input will be greatly appreciated. This is my work truck and if it dies I will not have a job. Please help.
to be honest, the proposed solution sounds like a bottom end rebuild which is roughly the same cost/work as the budget rebuild he did here ua-cam.com/video/R1qBJ8ZeOUA/v-deo.html
How many miles on this engine? What does the odometer read? Certainly it wouldn't hurt to drop the oil pan, check the screen for clogging and pump tolerances. That metal could be coming from anywhere like a worn camshaft lobe for example. Very difficult in this video to see the metal fillings/color in the oil sample shown. The oil does look super thick and dirty. I bet there is tons of sludge inside due to lack of regular maintenance. After you changed the oil and filter what symptoms were noted?
The oil was full of bearing material. The mileage I believe was 185700
'00 Durango with 186K miles, yeah its at the end of its life
you are definitely right
Was the magnum 318 less durable than the old 318?
Ozzstar you hit it right on the dot my friend. Jumping straight to an engine replacement is being a bad mechanic. Change the oil sending unit, and run some cleaner with the oil change etc. This would give a better picture.
Thanks a lot for the great helpful video, please do your best to continue producing videos, I appreciate this very much.
Excellent video, thanks.
My Crown Vic oil pressure never varied...it looked like an oil pressure gauge on the dash but turns out it is actually an oil pressure indicator. If you have at least 5 lbs of oil pressure then the needle goes half way up. Very deceptive of Ford.
Ford is a horrible company.
I was thinking of testing the sensor different. It's a variable resistor like a coolant temp sensor. short out that 5 volts and watch the gauge. or just unplug the sensor and see where the gauge is at w/ 5 v sig. alternative readings if the computer doesn't some how shut down the circuit. Tests the entire circuit. Your correct the gauge and wiring is good as the gauge is reading the same as the pressure sensor. But just checking the sensors ohms with varying pressure doesn't 100% rule out wiring and gauge.
Those a are valid ideas. In fact, usually I use a variable resistor to short the circuit so I can confirm proportionate variance with the gauge.
Yeah, that would work well never thought to use one. At the dealer we have simulators that generate volts which could work.
Great to see you making videos again. Not so sure on this diagnosis, but I could not hear the rod knock. What is the specification for engine oil pressure at idle for the 2000 Dodge Durango 5.2L? On my V6 Toyota Camry it is 4.3 psi or more and at 3,000 rpm it is 36 to 78 psi. Also, on the oil diagnosis, I would use Blackstone Labs before recommending an engine rebuild and pay $28 for their engine oil analysis.
This was a cold startup with the gauge failure activation being at 7PSI for this vehicle and we saw activation twice at end of IAC flare. There is no argument- this is legitimate low oil pressure.
How many miles on that engine? These engines are known for oil sludge buildup if oil is not changed regularly. Is it possible that the oil pick up screen is clogged with oil sludge?
in my 73 charger 318 i had low oil pressure after about driving 20-30 mins it would be at 40 then go to 20 so i took the oil pan off and saw the oil pickup was full of leaves and old silicone from previous owners while i was down there i rotated the engine looking to see my rod bearing were any good surprisingly they were still very tight and no metal material it makes the oil look kinda grey even when you showed your sample to us it looked grey and a bit like glitter normal old looks like its black or very brown right afterwards i put it all back together and it now stays a solid 60 psi on the oil gauge even after 1-2 hours of driving
Oil pickup full of leaves. Ok.
it was not too bad i bought a 440 a guy said ran and it was full of acorns lol he had run it the day before he said and i believed him because it was on a wooden run stand lol
witnesszer0 Would lve to hear your explanation on how these leaves and acorns are getting into an oil pan.
freaking hole in the back of the intake valley pan under the air gap intake squirrel will get into the darnedest places lol
What about the oil grade was wrong? My 2005 Suzuki Forenza start this problem after mechanic changed oil and and replaced timing belt Also started a knocking valve.
a knocking valve lol???? Oil grade causing low power?? Jesus.
Good video, please advise on why the oil pump does not generate pressure?
Man I really missed you! Thanks for this video!
I'm doing same thing with out the knock im guessing bad oil pressure sensor
maybe. what’s the voltage drop across the sensor showing?
Hey, you missed out on the EricTheCarGuy 2016 meetup. ScannerDanner was there, and you're favorite mechanic on youtube was also there; Eric O. from South Main. It would have been a blast to see you two guys hit it off.😆
I wasn't even aware of it lol. I really don't attend social events like that. I hate crowds lol.
Did you get a chance to diagnose some vehicles with ScannerDanner while you were in Pa?
Unfortunately we were unable to meet up. I have actually been to Pittsburgh 4 Times this year (my corporate HQ is there) but I haven't even had a chance to visit downtown. my schedule is so packed when I travel I wouldn't even know what city I am in if they didn't tell me where I was going !!!
That's unfortunate. It'd be sweet to see the two of you work your way through a diagnosis.
yeah, you could have used the load pro
CANT U SIMPLY PULL THE OIL PAN & REPLACE THE ROD BEARINGS & PUT THE OIL PAN BACK ON HOPE 4 THE BEST??? WOULD THAT RAISE THE PRESSUE A BIT ???
1996 Chevy Camaro Z28 my oil pressure gauge goes to zero after a while. I replaced the sending unit and nothing. I check the oil and it looks fine and I don’t hear any knocking and it’s doesn’t overheat and the engine sounds ok. I was told it could be the bearing? What other possibilities it could be?
Thanks for any information
what is the voltage drop at the pressure sensor?
If was not engine knocking already.can you check oil pump or change it pls?
You can however replacing an oil pump is not likely to restore pressure.
I wonder why you don't even mention the possibility of a worn oil pump? Sure it could be the big ends (indicated by the engine knock you mentioned). But surely after the pressure switch, next thing you'd check the oil pump - before doing a major bottom end rebuild?
because the oil pump does not create pressure. we can see the flow is sufficient but insufficient pressure is present. that cannot be from a bad oil pump.
So I just bought a 98 dodge ram 1500 and was told the same thing that its a sending unit but mine will sit at like 38psi then drop to zero for a minute then go back up to 38 then drop its like 30 sec intervals
Sounds like it may pulsewidth moldulated
good troubleshooting but would have been more helpful if indicated what pins on harness and sending unit meter connected to. as always though, helpful videos
I am quite certain I did mention the pins where the reference, signal and grounds. In fact I am 100% positive I mentioned that.
Makes one wonder if the pressure switch was loosened on purpose to hide the oil pressure issue?
I suspect it was replaced by a typcial non-diagnosing hack that was hoping it was just a bad oil pressure switch.
Incidentally this car did finally blow up this summer when the rod knock became so bad the timing was off enough the car wouldn't drive. Eventually the guy threw a rod because he had to floor it to even make it go.
matt Im in the UK ,but I suppose probably not much different where you are regards engine design ,but could it not possible there is a problem with the pressure relief valve, only a thought as you are sometimes getting pressure.regards joe
Hi, glad you are back. When will you do a video on radiator fan running for too long and stop for too short with no apparent reason. What would be the issue that makes them behave this way ?
Maybe a coolant temp sensor.
I just installed some Boush Mechanical gauges to my 283 Chevy Sm Block, it has 37 pounds of pressure at start up at 1500 Rpm, Book say should be 38 Pounds at 1500 Rpm. But after warm up, it drops to like 20 pounds?
Thank you 🌷
Some of the Chryslers of that era have "fake" oil pressure gauges. The dash gauge either reads in the normal range or it reads zero but never in between. That sending unit appeared to be variable, and that's what the wiring diagram shows for that 2-wire sending unit, but the dash gauge was either zero or 30 but never in between. Kind of strange.
It's too bad there are dishonest people that would rip someone off like that. Sad. That sending unit looked pretty clean like maybe someone had replaced it and realized there was a bigger problem and dumped it on someone else.
Precisely what I suspected. I figured the broken sending unit was result of some 98%er changing it on a guess.
On what data do you have?
johnaclark1
Crooks who knowingly sell defective vehicles without being honest are scum of the earth.
Hi dear teacher, I have 99 jeep cherokee with low oil pressure (check gauge light) with new 3 wire pressure sensor. I checked the 5v ref. and the ground and they are OK. I check the continuity of all 3 wires using the wiring diagram and they are Ok. I extended separate signal wire from the sensor signal to the control but didnot fix the problem. The sensor signal voltage is fixed at 0.17 V with plugged connector. I tried to get 5V ref. from the ECT sensor through my test lamp and put it into my unplugged connector signal and also there no respose. If the oil pressure is ok, is there any possible causes except bad pcm?? Im I a good student?
Yes you are a good student. You did very well. You must have the connector unplugged to see the 5V signal. Measure with it unplugged and if you find 5V then your next step is to use a gauge to measure the actual oil pressure mechanically. If however you don’t have 5V, then there is some type of wiring issue. It should be there.
@@SchrodingersBox I checked the 5V and the 3 wires and the actual oil pressure and they are all OK. Thats why im sending you. So, is it now the PCM or still there is something to check?
it’s not the PCM. you either have a faulty sensor or legitimately low oil pressure.
@@SchrodingersBox many many thanks my perfect teacher. Finally it was a bad new pressure sensor. I replaced the new sensor with another new one and it works great. Many thanks again
@@SchrodingersBox but how can I test the 3 pin pressure sensor. Is there a prober method to bench test this 3 pin sensor. Which resistance should I measure?!
I have a 2012 ram 1500 5.7 hemi. Oil pressure fluctuation from normal to low with warning light. Slight temp increase. Stuck 500 miles from. Home need ideas
This is a simple one. Just Check the mechanical pressure and see if it correlates with output voltage drop across the sensor.
The old "bad oil pressure sending unit" excuse is never a good sign. I recall taking an old truck for a test drive and it was smoking like crazy under the hood. He told me it was just the valve cover leaking... yeah, sure.
On my kubota generator diesel engine, if my oil pressure goes below 10 psi it shuts off automatically. Also if the engine gets too hot over 240F it shuts of too prevent overheating. I dont know why they dont have this on gas engines.
Yeah it should be a default that on overtemp or low oil pressure the engine shuts down. It's going to shut down anyway when it blows so why not save it!
the specification of the oil pressure at the specific vehicle is 6psi at idle and 30-80psi at 3000 RPM with engine at operating temperature. you might double check that sensor .
Absolutely incorrect. First off the evidence is irrefutable that this is NOT a sensor issue as evidenced by the obvious symptoms demonstrated. Second, the curb idle at cold startup should easily be 40psi. Third, as evidenced twice in the video, and as documented in service manual, the gauge failure trigger is 7PSI. We in fact saw this actuation twice as soon as the IAC stablization occured. Electrical and flow confirmations were equally irrefutable.
To say this could even possibly be a sensor issue is absolutely ludicrous.
so you saying PRODEMED and ALL DATA are wrong o and also IDENTIFIX has the spec..
david cisneros I am saying use logic and reason. Look at the evidence presented. It is IMPOSSIBLE based on simple, basic, remedial understanding of fundamental operational concepts that the problem with this car could even theoretically be a bad sending unit. You will need to explain the symptomatic etiology otherwise you would just look foolish saying what is obviously contraindicated by multiple examples.
what I'm saying is base on the oil pressure readings been at 10psi and with a malfunction gauge at the dashboard you might have a bad sending unit and not oil pump cording to all data . I'm not saying you don't have bad engine do to other mechanical issue.
What you are saying is necessarily contradictory. An engine with the evidenced bearing damage and knock MUST have excessively low oil pressure. This is basic fundamental fluid mechanics, my friend. So even if the sending unit was bad, which it is definitely not as was irrefutibly evidenced in the video, it would be irrelevant anyway.
Ignoring evidence you don't understand makes for an illigical thought process, albeit simplified.
my Ford Explorer is doing the same thing with the m Dash on my oil it seem that there's no oil and there is so mine's a little different my truck does not have a knocking sound to it at all and what would that be
Then I would IMMEDIATELY diagnose the issue. If it's actual low pressure you may be able to intervene without catastrophic damage and get by with just bearing replacement.
what causes this. my wife's car just died and this is what it was doing. I thought the sensor was bad because I new the oil was full because I just changed it and it was running fine.
As described in the video your variables would be worn bearings or faulty sending unit or fault gauge.
Schrodingers Box I guess I meant what causes the actual low pressure not false indication.
HillbillyMatt ExtremeDIY When the engine bearings are worn the space the oil passes through is enlarged, which of course exponentially reduces the pressure.
Schrodingers Box aha. that makes a ton of sense. I am so hooked on your channel. as you may be able to tell by my name I enjoy pushing conventional rules of DIY. as you probably know when you are rengineering the conventional you have to do all of the homework. I appreciate it when I find a good source of detailed knowledge like your channel.
you are very thorough and you make it understandable. thank you.
I was trying to find the video that you refernced in your extreme budget engine rebuild video, in which you discuss why rod nock is an absolute engine replacement/rebuild. what is the title? I tried searching "schrodingers box rod knock" to no avail.
HillbillyMatt ExtremeDIY Welcome to the channel! Try searching the channel itself. It is under the "about" tab on the main channel page if I remember- there is an option "search channel" as opposed to searching all of UA-cam.
Looking for advice, 02 altima with fuel trims at negative 15 to 20 %, code 0300, O2 V at 3 to 6 V. and long crank start after warming. fuel pressure good, compression good, does not stall. unplugged vacuum line and trims improve but o2 voltage remains at same levels. ??
What is the LTFT and aSTFT curves at idle vs load? You cannot tell anything without that.
the STFT I mentioned is at idle, with LTFT at neg 10%, under, load during take off it goes up anywhere from 0 to + 5 % at best, once settled STFT goes back to as low as negative 18%, unfor did not check LTFT,
I have been leaning towards a leaking injector, would this cause the random misfire?
Oscar Hernandez Oh perfect- what is your data you have indicating a leaking injector? That helps. Was it a static fuel pressure test?
well at this time I have no tools to test injectors, (I might be jumping to conclussion)I stumbled upon your videos not long ago! been reviewing the diagnostic series, I might need to test fuel pressure since I only saw pressure while cranking, it had no pressure when switch at on position!
in my case the problem (very persistent oil pressure warning on idle sometimes with miss fire on all cylinders but not always) was dirty vvt adjuster/magnet! Litle bit of parts cleaner sprayed in each hole and problem is solved!!!
Hi , I suspected the oil pump filter clogged .Thanks
Time to drop the pan and take a look!
Totally my preference too! But on some models, dropping the pan is very time consuming. The nice thing about this method is there is no need to drop the pan. We can confirm the issue without even getting under the car.
The knock and the chromium visibly present (indication of ring wear, exacerbated by loose rod bearings which allow the pistons to "slap" around and wear out the rings) in the oil were already indicative that the engine is worn out.
Douglas Self yeah, he said that
I have a 98 chevy 5.7. At idle warm my preasure is a little under 40 on gauge and of course when hit throttle it goes up but never drops lower then like 38. Know it's just a work truck and never goes on high way and I dnt plan to keep it much longer but I do need it to perform for the next couple months. Should I be worried? Done oil change distributor plug wires could almost all sensors on engine I just rebuilt the front end like stearing components. The lower intake needs to be done the engine only has 150k on it should I RIP the engine out and find a used one with lower mileage and before install change intake gaskets and oil pan gasket and run it if I plan to keep it or just run it till shes dead. I have a spare engine in a parts truck I bought that runs but has 230k on it idk if o should just pull that do the same same lower intake and oil pan gasket possibly spider injectors and slap her in it's just the mileage it has on it and it's a old plow truck so I'm sure that engine did alot of idling. Just dnt know what rt I should take junk yard engine or one in parts truck that has 230k or just run mine with low oil pressure. Or is 38psi at idle ok?
it’s fine. that’s normal.
Would a " good " salvage yard engine be less expensive than a rebuild ?
Thanks , :-)
Wyr
God bless
Oh way less. way way less. I get salvaged engines complete with accessories for $200.
Is it possible to make my 2000 Golf 4 shoot flames or backfire, if i rev up my engine, then turn off the ignition and press a button connected to my fuel injectors and turn on my ignition again to make it shoot flames? Just like old cars with carburetor
Of course- run the car with a maxed negative fuel trim and insert spark plug in exhaust. Have fun.
Perhaps the problem in the oil pump or the filter of oil needs to be reblaced
What do you think about that you didnt check them ?
Good thought but the bearing clearance confirms the cause.
isnt 10psi of oil pressure normal at idle speed? im pretty sure that on the mercedes m103 even 5 psi can be within spec at idle.
Average 'good' pressure would be (and this is for a well used engine that is still in good shape) 10PSI for ever 1k RPM. That's a bit of a minimum pressure. Combine this with the pressure dropping below 10PSI which it did a few times-and the bearing grit in the oil. The engine is done. Needs at least a basic bearing set-which while you're in there, do the job right.
I see someone just mentioned "6psi" for oil pressure being good at idle. Me thinks I'll stick with the 10psi at 1k. If it's that low at idle, and you tromp on the gas? It will be one hell of an oil starvation problem. (It takes a tiny bit of time before the increase in RPM equals increase in oil pressure. Not a lot of time mind you! But enough it could accelerate the damage already done)
Tedybear315 well the engine i was talking about (mercedes m103) shows 6-8psi at 600rpm idle with a warm engine. as soon as you hit about 1500rpm the oil pressure builds up to about 50psi. the instruction manual says that this is how its meant to be with this engine.
Not on a cold startup- that would be for fully operating temp andf even then, anyone buying a car where a dummy gauge like the one on this car indicates 4 would be foolish.
Schrodingers Box oh, i thought the 10psi you measured was with a warm engine. on cold startup 10psi is way too low of course.
What did the customer decide? Is he going to drive it til it dies? rebuild the engine? or find a salvage yard used engine?
He decided to drive it until he can hopefully save for another vehicle. I agreed to go with him to ensure he gets a much more reliable vehicle when he is ready.
He definitely will use your expertise when buying another vehicle. It's a shame this one will end up in the scrappy! I hate to see cars die!
Thanks mate!
Wait so u drove the vehicle into the shop and didn't notice the oil pressure gauge was haywire?
Wouldn't the first test be to check the oil dipstick ??
No because we confirmed oil level light operation and function.
dang just did engine and another mec told to me it's leaking on oil sensor. why that should of been replaced with engine. ahh. and the power steering pressure line leaking too and 02 sensor, engine light on. ahh . Gosh when I got it back from mec the oil showed none. I put lucas and oil. took it to another shop they said add one quart more oil said maybe dip stick is maybe wrong one.
Sounds like you car needs to be on this channel... and your mechanic needs to watch lol
Same like the ram pressure sending unit broken in half but it's not the case here
How many times have you found junk, tape, or other methods of covering warning lights that ended in disaster?
I have an 03 ram 1500 with this problem. What bearings are you referring too that need to be replaced?
the rods and mains.
Hi, i rebuild a gm grand am 1999 2.4l ld9, troubleshooting is i fill up the engine oil full of the gadge, oil dipstik ok but when i start the engine few min and stop, i take a look on the dipstik again and oil is very low, do you have an idea, where the oil goes, no leak everyting seal on spec. Thank’s. Ben
I normally diagnose these using fuel trim analysis to look for oil in cylinders.
Schrodingers Box think there is oil on the cylinder, i check the compression and everyting perfect head and valve.
it won’t be a compression problem. possibly a seal problem. anyway when you see the fuel trim show a proportionately rich curve compared to load, that obviously would be indication on where to suspect the issue.
Schrodingers Box yes i have to check more specific fact, i am going to take a look and see the troubleshooting, when is done i reply to you and see what i found thx a lot. Ben
Im having a similar case with golf 4,however the car won't totally start
No crank no starts are way easier to diagnose.
Which is a good oil pressure in car? I have 75 on idle and 80 whit gas it is to high ore good?
V6 3.4 Camaro Gen 4
that’s really good.
Thanks 👍🙂
Would a higher volume oil pump be a budget hack to extend the life of that beater? More volume would force up pressure right. Don't judge I just woke up.
I mean if it didn't already have rod knock
I have a lexus IS350 2007 with low pump pressure, i have bought 3 different oil pumps and no change, the car starts fine, but the oil pump pressure is very low. Pls what do you advice?
Why are you replacing the oil pumps- what is your evidence the pump is the issue? What is the voltage and amperage at the pressure sensor vs actual mechanical pressure?
@@SchrodingersBox the mechanic did a pressure test and said it read 70psi.
Then there is definitely not low oil pressure. Test the bias voltage at the sensor next.
Hey schrodingers box I live in cs and have a engine noise that seriously needs to be addressed is there any way I can get ahold of you I need help
No need- just find the source of noise and confirm through visual confirmation. There is no skill in diagnosing noise- you just have to tear into it. See my other engine noise videos and it's very easy to diagnose even with no skill or experience.
Well the only issue is that I live in an apartment complex not a house. They don't like people doing much of anything on cars here and I have limited tools. I should say I would really just like you to look at it since I am going to have no choice but to take it to someone and have the most confidence in you rather than typical part changing shops. Its an 05 neon standard trans and it sounds like gears want to fall out when I'm coasting in neutral.
The moral of the story is that you should *never* believe what the seller says 100%. Always take what they say with a pinch of salt and use your common sense and judgement. Or even use it as a bargaining point to get a better deal as you are taking a risk. If in any doubt and you are not willing to risk it (you can't fix it cheaply yourself, for example), walk away.
If it really was just a pressure sender unit, the seller, in theory, should have had it fixed as it's a cheap and easy repair - why would he have an obvious fault that would mean less chance of selling the vehicle, and getting a lower price for it?
Correct- and in fact, I believe the seller did replace the sending unit which is why it was broken, and that confirmed to them to unload the vehicle.
I hate crooks.
Rebuild? Gee.. well, I think if owner is on a budget, a junkyard engine might work, find a rebuild-able on craigslist or eBay, find a shop willing to sell a donor engine, other options.
HELP! I have a 2008 2.2 litre Ford transit van. The oil light is on. I have carried out an oil pressure test and get in excess of 60 psi. I have installed a new pressure sensor and the oil light is still on. It goes off if I pull the sensor wire off so I don't think it is the wiring. Any ideas? I am stumped at the moment! The engine sounds as sweet as a nut and the oil level is ok.....
What is the reference voltage showing? Clearly it’s a reference issue.
@@SchrodingersBox I will take a measurement just as soon as it is warm enough to go outside. We are having an extreme cold spell here on the Isle of Man. Thanks for responding, it is much appreciated.
@@SchrodingersBox I have just measured the reference voltage on the wire that connects onto the oil switch ( with it removed from the oil switch) and with the engine running. It is a fairly steady 14 volts. As soon as I reconnect it to the oil switch the oil pressure light comes back on.
14V????? I never heard of a 14V reference. How did you get 14V on a pressure sensor?
@@SchrodingersBox Is there a difference between a pressure sensor and a pressure switch? I am under the impression that the oil pressure switch has positive supply voltage connected to it. With the engine off and therefore no oil pressure the pressure switch allows a connection to chassis earth and the oil light therefore comes on. When the engine starts and the oil pressure is present, then the oil switch breaks the connection with chassis earth to put the oil light off. The battery system on my UK vehicle is nominally 12v. I am guessing it rises to 13 or 14 volts when the alternator is charging the battery. I must admit, I was not expecting 14 volts. The vehicle manual, that I have does not give any information on this particular circuit and oil switch.
How much is a motor rebuild
That test on the pressure sensor only showed it was alive, Without knowing what pressure gives what voltage it is hard to say that it is working correctly. I do agree that the Engine isn't long for this world though. :(
Correct- I was only showing demonstration of how to look for sending unit functionality. It is actually irrelevant in this specific application.
If the engine oil is low all it needs a new oil pump why do you say the engine is shot
@@jessemichel7073 the most common cause of low oil pressure is worn bearings, those are lubricated internally by oil passages. If they get sloppy too much oil flows and you lose oil pressure. The sound of the engine combined with the metal particles in the oil leads to the conclusion of the engine being shot.
Hi matt, I am having a similar issue. The oil in the cylinder head is very less when the engine is running. I hear loud rocker arm noise. Could this be a failing oil pump? I changed the oil filter but no changes. No particles in the oil. Could it be a blocked oil gallery ?
What if you don't have a oil guage?
Then you can’t get pressure data.
if we came from other side, Bad oil bump can cause inefficient lubrication and bearings is going to wear out. Pressure will fail down with time, am I right? because this is what happened to my Nissan Z I guess.
Low oil pressure is usually or almost always a worn motor and the bearing clearances are way out. One way to confirm is to check the oil for metal as he did.
Hi,friend..I have zero oil pressure when i start my car,i need to accelerate to flow the oil.why does happen this my friend?thanks
What was you resistance on the sensor during these variables?
@schrodingers box
Can you do a video on high oil pressure diagnostics and what kind of damage it can cause
Which of your videos can I view to know what to do when fixing my brakes
My brake replacement for beginners video. easily found if you search my channel.
Curious what drop-light you are using...Looks to be a LED type... The incandescent one I use with metal cover is hot enough to cook a steak on it and sometimes touches my ear under the car...
something i found at Sears a few years ago.
Hi, love your show have a quick question I have a 350 Chevy small block I have a autometer gauge hooked up to it when I started up my oil pressure is about 30 when it's warm what about 20 minutes it goes down to about 20 is that normal
Hell ya, thanks for posting man!!!! missed ya . Half the time if you grab a junkyard v8 with decent miles on it, it's cheaper than a full blown rebuild after u buy the kit and all of the nicknacks. Unless you just go for bare bones what u need to get by or whatever. Looking forward to seeing the budget rebuild if it is in the young mans budget. P.S. i heard that lieing is bad for your teeth, the previous owner needs a pop in the mouth to prove that theory.
Lol agreed on everything! I have done many dozens of salvaged yard swaps- it's how I started in this hobby in fact. I used to swap an engine for no more than a $500 investment total for everything including new gaskets and fluids. But I no longer do major work now.
Rhage73
Do different oil filters make a difference in oil pressure
Nope
I have a 2006 chevy Silverado with a 4.8 and 119,000 miles, it runs good but the oil pressure hangs around 30-35 when warmed up. What could I do to get it back up to 40 psi at idle?
@@SchrodingersBox
Are you going to try and rebuild the motor or are you guys going to find another motor? If you rebuild this motor are you going to continue the budget rebuild series from the ford?
Thanks for doing these video's, they are really helpful.
Unfortunately I no longer do rebuilds or swaps. Owner is on his own with this one
Ok thanks. Do you have a paid channel?
Yes he does have a paid channel. It's very good.
Thanks DAvid! Good to see you!
Schrodingers Box Likewise, friend. :)
Great video
Hook up a mechanical oil gage as a back up test.
Always enjoyed your videos; having issues with my car. Good oil pressure but no oil to lifters. Any input please?
How are you measuring oil pressure? It’s hard to imagine you have good pressure and no oil to top end. And if you had a clog or something the pressure would be really high.
Are you measuring using a mechanical gauge at the oil pressure sensor port?
@@SchrodingersBox Thank you for reply!! Used a high quality guage to read pressure at sensor port; if it was blocked oil gallery or turned bearing? Scared but need to know; car has 3.8 supercharged with 230km.
How are seeing no oil to lifters? Is this a overhead cam or pushrod engine?
@@SchrodingersBox I removed valve covers and let engine run for about 90 sec; oil pressure was 50psi but no oil to all lifters. Then removed intake and lifters looked ok, also no oil in the valley. Oil pickup screen and oil pan were pretty clean
@@SchrodingersBox The car is 2006 grand prix with supercharged 3.8l, series II. Is it possible to manually pump oil through the motor to c if it has a clog?
Fill it up with 20W50 and a bottle of gear lube and get that baby on craigslist!
If he is strapped for money can you do a junk yard engine swap for him. It might save him a few hundred bucks. Just my 2 cents lol. Your videos are great!!
several years ago I did tons of major repairs like that but nowadays due to time constraints I no longer do rebuilds or swaps. He's on his own unfortunately.
Oh that's too bad. Well I do hope he gets it fixed before it turns into a full blown spun rod bearing. If it's not that already.
Yikes! Sorry to hear that! Too bad you went through all the work of the radiator only to find out the engine is shot. I feel bad for you, he shoulda said something about the low pressure and or knock first.
For Sure!!!!!!
also I have a 2011 2SS Camaro 6.2 L and it is pulling the code saying its my oil pressure sensor
There is no such thing as a code that says it is a faulty oil pressure sensor.