Sir I am junior technician.now i want to work with you sir.because your diagnosing skill levels are very impressed me sir.i am alltime use your FASTTEC method to diagnosing the problems.your doing very good job for young technicians to grove sir.
I had a similar case with my car. Bad radiator: replaced. Bad hoses and water pump: replaced. But still losing coolant. We (a mechanic and i) did a compression test and all normal. The mechanic after chasing ghosts for a while he said to me "I bet you anything it is a blown head gasket, Im gonna open this thing, if is not, no charge" and was right. The head gasket had a tiny little crack, and there was no sing of water in the oil or white smoke on the exhaust, but was leaking coolant to the cilinders. And he did all the proper testing on the cilinders. Great video as always Matt. Cheers.
One of the hardest things for some people is to change their plan of attack when it's not working out. Many (most?) would attempt to make the "facts" fit their hypothesis (and then fired the parts cannon in the general vicinity of the engine bay) instead of acknowledging that they may have been on the wrong track. Glad you're not one. Cheers, Matt. :-)
I once had this same exact disappearing act with the coolant no visual puddles and all the previous tests you did I did I couldn't find it Until I overpressurized the system and discovered it was an oem hose clamp that had been cracked. This broken clamp was the find and fix. Mighty Max has a pressurised kit that comes with a way to test the cap as well. So my 2 cents is do another pressurise test but go over what the cap psi is telling you the Max is .that's how I found where the leak was. The oem clamp was half broke, just tight enough to keep fluid in but not tight enough to stop boil over.
Dear Eng. Mat, I did not see your entire movie as I needed to do something else, but I thought to inform you that sometimes a heater core could leak a very tiny amount, where in some instances you could find out if you operate the heater and put the air dial on front windshield where you can notice a little bit of fog being emitted at the windshield. Also you might be able to smell an ugly odor under the dash toward the center console. You have to figure out how to air pressure test the heater core after disconnecting the inlet and outlet of the heater core preferably from the engine and not from the back panel so as to enable you to block one side and air pressure test the other with a gauge and hold it for few minutes, noting that heater cores do sustain pressure maybe up to 20 PSI or it can burst, so maybe 10 PSI is enough (investigate this before commencing), I believe you said that the water pump was replaced, and as you may know that most water pumps have a sort of pee hole that only slightly drip when hot and due to heat the dripped coolant drops might vaporize before being catched on either the floor or any panel beneath, so maybe if the heater core is checked okay to investigate that possibility. Advise the client to keep a distilled water gallon at the back of the car, and every morning before he start the car to check the coolant level and top it if needed. also if he work for 8 hours and before he start the car to get back home to check the level too. This at least for few days to build an estimation as of how much the amount of coolant loss. Take Care and enjoy your time. John Jack Kaplanian from Jordan / Middle East.
A good thought however a leaking heater core would be evidenced with the decay test. The decay test was absolutely negative with not even 1PSI drop in 5 minutes.
Good on you for not charging for the simple rad swap. That says a lot about your character and will no doubt pay off in the future through more sales from your loyal customers, not to mention referrals. I like how you diagnose issues to save the customer money.
Build pressure in the coolant system and check that the max is correct as stated at the cap, that the max pressure is maintained. One possibility could be a jammed rusted cap that allows the pressure to go beyond the max pressure. Nice video!!
Something "similar" happened to my dad's xterra. He wanted to change the water pump. I did several test and discovered the radiator was clogged, increasing the pressure and the weakest link started to leak one by one. The car was having a stroke. Anyways I just wanted to say Thanks for your teachings. I've learned a lot from your videos.
I was really looking forward to another upload! Thanks Matt. At the moment I am chasing down an issue on my bmw n47 Diesel. It used to idle rough once the engine reached operating temperature.(misfire like symptoms) Th mass air flow values I got from my obd scanner didn’t seem very consistent. That’s why tried being a parts changer(shame on me) and installed a new maf. Testing the maf was outbid reach for me because I would’ve needed an oscilloscope. Th issue was instantly gone after that and stayed away for half a year. Now the same symptoms still sporadically appear. The next step for me whould be to assamble an injector testing kit, which compares the amount of fuel which every injector sends back. It seems like one of the injectors seems to be working okay ish but not perfectly. For now I’m using liquy moly diesel fuel system cleaner with every filling of the tank. That solved the issue short term. The funny thing is I only got one code while these symptoms appeared which was indicating a rich fuel-air mixture. (Didn’t always appear together with the symptoms) (yes, the car has a broadband oxygen sensor) If you don’t have time to answer this long comment, don’t bother. I just wanted to share what I’m doing. :) Best regards from Berlin :)
When the question was first asked my guess was the timing chain cover gasket. However with all the negative pressure tests and no evidence of coolant on the ground I’m stumped too, will be following this for sure.
I agree, the next step should be to confirm the coolant leak, it might be that the puddle under the car that the customer sees isn't actually coolant. Also, if you suspect high cooling system pressures is causing components to fail then you could measure the coolant pressure directly during normal operation, just attach your coolant adapter and take it for a drive. If you see high pressure, then would be the time to find where its coming from. Like you said, it might be that the head gasket only leaks when up to temp?
Matt, you will be AWESOME always in my book brother and thanks for showing all this really interesting problem hope will be another video to see what is the problem 100% and thanks for sharing.
Matt, Have you considered a first look type pulse sensor and scope on the coolant tank with engine running? You can make one for about £5 or buy one ready made. It will detect very small pulses in the sealed coolant system, you can even set a channel on scope for cylinder reference
A sticking thermostat will cause inadequate cooling and overpressure with secondary leaking. Some have a second valve that allows coolant to bypass the radiator when cool. It is not an easy diagnosis without real time cooling system pressure measurement, so many would just swap the thermostat. Perhaps it was replaced with the water pump?
I had a bad head gasket in my 2005 Altima and I looked in the spark plug holes with an inspection camera. Nice shiny piston gave it away. An intake coolant leak will show the same. If enough liquid enters the cylinder you can get hydrolock. Some liquid could give a hard start due to high compression.
Interesting note... sometimes there can be diferent water pumps with diferent flow. I know in the cummins world there a bunch of diferent ones that will fit but a 4bt pump will be lower flow than a 6bt or 24v. Sometimes guys actually trim the pumps on high rpm 24v cummins builds because they will over pressure and blow the frost plugs out.
After that Toyota which passed all the head gasket tests (leak down test, compression test, and coolant chemical test), I always second guess head gasket tests now. Im traumatized now lol. I had to use the camera to look inside the cylinder and see the coolant inside the cylinder after sitting overnight.
LED light rod? Honestly, Matt how could you be so naive? You've paid $200 for a lightsaber! On the plus side, I've heard you can use lightsabers to seal head gaskets. Seriously though, it's great to see you back in the saddle again, man; UA-cam hasn't been the same the last couple of months.
I was relieved to see this was not going to be an electrical issue video because I’m still trying to get my head around the basics of that area. Then I realized this also looks like it’s gonna be tricky, even though I understand everything involved. Two potential areas of solution occur to me. The first is more basic than anything you covered, Matt. That is to confirm customer complaint first before moving on to any diagnosis. I don’t think you personally confirmed the complaint (for whatever reason) and you may be chasing your tail for the wrong reason (heater/AC, other). The second is potential water jacket blockage within the block. Similar to pressure cap malfunctioning, perhaps this might cause an overpressure condition. Pure speculation on my part as a total novice. Too bad some viewers don’t pay closer attention to your entire video, as at least two suggested chem test which you clearly listed as having done previously off-camera (but definitely something I was going to suggest until I saw it listed). Can’t wait for Part 2! Oh, if all else fails, then what’s left is what initially seemed implausible - a major set of coincidences. 😉🔧🧰
Not sure if you mentioned the year of the car, but It appears to be 2005-2009? ITs 10-15 years old, plastic/rubber is just plain worn out. The water pump is replaced, up to full snuff and working as it should putting strain on an old system is a variable. Another variable is pressure cap not venting properly and over pressurizing not letting coolant in/out of the Degas bottle.
I'm still with you on the leaking head gasket. Did you take off the thermostat during the leak down test? Engine cold during leak down test and it would have closed yes? That's why no there were bubbles coming out of expansion tank
On my Honda Civic.-Compression test was good but it kept blowing hoses/rad. Actually measured CO at radiator with a gas detector.(Got ther idea from your video with CO2 detection) Car is functioning with stop leak and new radiator for now. Have to add coolant every 75 miles
I wonder if there is a way you can check the pressure in the coolant system to validate your suspicion that the coolant system is being over-pressurized? However unlikely it may be, it's always possible that these series of failures were just a coincidence.
I am thinking coolant leak in intake manifold to exhaust port. Only shows when the car is warmed up to temp. How about compressed air at the tail pipe and look for bubbles in the coolant reservoir or in oil? Note: Im not a Mechanic but I do own a Buick.
i was just about to suggest the same, although I think Matt would've probably went over it the first time he had the car EDIT: scratch that, the new radiator came with a new cap.
Beat me to it. I would suggest testing it with more than one style of cap tester too. There's a cap tester that goes to the pressure tester you currently have that requires you to screw it in and there's also another style that's included in the pressure test kit at Autozone that you push in to the pressure tester in the kit. I would try both types since I got more consistent results with the one in the Autozone kit. The other style just showed caps I knew were bad as completely fine.
i used a coolant cap with a bicycle valve put in and perfectly fitted with no leaks and pumped the bike tire pump to pressurize my system it worked well :D
From 11:10 you talk about your suspicion, that the car has a head gasket failure and that's causing the leak. This might be the case (haven't finished the video yet), BUT I want to share my experience with old cooling systems at this point: - My 2001 BMW E46 with now nearly 260.000km started developing coolant leaks about 10.000km ago. First the water flange at the rear of the engine towards the cabin heater got leaky because of a brittle O-ring (10.000km ago, a typical problem). Then a couple of months ago the radiator started leaking because the aluminium corroded too much (also a common problem, you can see the coolant passages swell, sometimes the passages even delaminate from the fins and start to bow down!). While fixing the radiator, I noticed that the plastic connector of a hose had a spot where the plastic got brittle and leaked. This seems to be a common issue as well. BMW claims that the coolant is good for the vehicle lifetime and does not need to be changed. At the first major leakage, the coolant was changed though because every shop (later I did the repairs myself) filled it with a different coolant, resulting in a nice, brown colored coolant.. - My first and second 1994 Honda NTV650 had a similar story. There were small leaks when I got the bikes and after changing the coolant, there were even more leaks. I went ahead and changed every rubber seal because ALL of them were hard and brittle. Both bikes had brown or grey, fishy smelling coolant in their systems. -> On the Honda NTV forum I created a list with all necessary seals because many other owners had similar experiences. - Similar story with my 1984 Honda VF750F, started leaking after changing the oooold coolant. => Some manufacturers claim that coolant does not need to be changed but I find that this is not true. All the vehicles with improper cooling system maintenance had issues with brittle seals and after fixing one leak, another one is not unlikely to occur. Sometimes a coolant change or filling up coolant can trigger that as well. I learned (and still do!) a lot from your videos and as a fellow researcher, I believe that a big part of Science is learning from each other and bouncing ideas back and forth. So I don't want to say that you're wrong but just share my experience for consideration :)
Just trying to help .... something to condenser ! trying to find a head gasket leak with either a in cylinder leak test or relative compression test is unreliable .. compression when cranking will be at the most 200psi cylinder leak test is only 100 to 150psi depending on the compressor ... BUT when the combustion gasses are ignited cylinder pressure can reach as high as 1800psi ... so if the leak happens at 300 psi you will never find it ..... chemical annalists of the vapour above the coolant is probably the best way .... you could also monitor the pressure build up in the cooling system if it exceeds the pressure cap rating that would be of concern Best regards JF
I have a blown head gasket pressurising my cooling system at high operating temperatures (bubbles observable). Its my only car and I'm not in a position to repair it or buy another car. I re-routed the fan relay grounds from the ECU to two rocker switches beside me in the centre console. I maintain the engine temperature manually (risky I know) and no more leaks. Granted, now my ECU doesnt know when the fans are on and it won't compensate with IAC but I keep an eye on the idle speed and the oil pressure. I think you should let this car get hot and see how it behaves. Heat, as I'm sure you're aware, will cause dimension change in the head, the block, and the head bolts, and may be relieving head gasket clamping force.
Like another person commented, it could be a radiator cap stuck closed and over pressurizing the cooling system. I think this may or may not be detected by by a pressure decay test as it could be leaking under a pressure higher than the standard testing pressure
I think your mistake was focusing too much on head gasket problem. These kind of problems are frustrating I know that for a fact. I hope this mystery resolves and does not cost a lot.
How the heck did I miss this 2 part masterpiece? Was this title a one off from 2 girls 1 cup? 😂😂😂😂💩💩💩💩 alright I'm done clowning, let me watch this and try to get this pea brain of mine to learn more from such a great teacher!
Hi,thanks for the videos you sharing to us. I will suggest you to try the combustion gas leak tester, the one with the blue fluid,which when detect gas,react ,and turning to yellow. It's working very good, and of course, it's a time saver, specially for this type of engines, which involve a lot of work to test for head gasket. maximum in 5 minutes ,you know if you have head gasket. you just remove the radiator cap, to test the system. nothing else.
Bet money jiffy lube screwed up, almost certain without even knowing. Radiator cap not releasing pressure or someone used distilled water eating the metal of its minerals causing failures.
Monitor coolant pressure with engine running while watching temperature. Combustion pressure is 10x what you were testing with. Have seen videos where they use a pressure transducer on the cooling system....expensive tools. Not sure what the chemical test you used checked for...carbonic acid? Not good if coolant is getting into the cat.
I watched this video with much interest as unfortunately I have a 2013 Ford Escape (first owner) with 130,000km (Canada). My coworker blew her engine at 140,000km on the same model due to the notorious coolant-leak-into-cylinder-chamber issue on these models. I am expecting my engine to blow as well in the next year or so. It seems the money required to fix this issue is not warranted considering all the other issues this car has developed since new. Regardless, the cause you tracked (blown head gasket) was my first guess considering the history of these cars. Considering you haven’t been able to prove this is the cause, could it be a plugged rad or cooling jackets that is leading to higher pressure in the upstream cooling components, including like you observed, the pump (highest pressure), then the hoses?
Could it be that the system was not properly bled of air when the radiator was replaced, and it isn't really leaking, just burping out the air as it runs? Just asking, I am not a mechanic.
@@SchrodingersBox I don't understand your answer. If there are no leaks, it would pass the decay test, but the coolant level would drop as trapped air was worked out. Obviously if the coolant loss continues, that's not it.
it’s because the issue with coolant loss happened even after I did the pressure decay test. the pressurization of the system would remove any air pockets if they existed.
Sounds like my POS Ranger. Alum Heads on Iron Block no bueno. Heater core went, then Radiator went, heater core with radiator went this time huge cloud of steam out the tail pipe. Cracked heads, new long block, just doesnt run right compared to other trucks money low mile pit. Why not start with a chem test?
What if you have a thermostat sticking ever so slightly? Doesn't make much sense if the car does not overheat but worth checking. Does the car overheat or just loses coolant?
@@SchrodingersBox that leaves sizzle and heater core. Ez yest if you got time and good weather is to bypass the core fore awhile and see if leak stops. Good puzzler tho. 👍
Thermal expansion of dissimilar metals, e.g cast block, aluminium heads etc once heated and expansion has taken place, OEM composite gaskets can't make up the variance of the dissimilar metals seperating. Definitely head gasket or intake leak. Will only show itself at operating temp or above. Most likely excessive air in the system over pressurising the cooling system which causes further detriment to the already compromised gaskets clamping force.
Merely my theory. Unsure of the particular engine's metallurgy as I'm from Australia, don't have them here. However we have the 3800 Buick which is all cast besides the aluminium intake manifold. Have had the case above where my intake manifold gasket was compromised but only after the engine was warm, the aluminium expands, cast does, but not comparatively. Had a coolant leak into the combustion chamber, O2's pick up on the variance, start over fueling and bam your Catalytic converters are dead.
I got a off the wall question for you. Do you have a business setup or anything of that nature or is just drop it off and I charge X amount per hour plus parts?
Well hello there, where have you been 🤣 long time no video. I’d be very suspicious of the two cylinders that were side by side and 10 psi lower than the others.
Has the expansion tank got a hairline crack in it that is opening when hot only company has a lorry doing this garage could. Not find a leak, I told them it’s was this months before as when engine overheated the water was under tank and on top of engine
That’s a puzzling one Matt! I’m not sure where I’d go from there? 😂 I’d be suspicious of the coolant cap because you remove that from testing when you use the pressure tester. Is it running hot or overheating? Would that cause it to consume more coolant? I hope you update us lol it will drive me nuts 😉😂😂
Nice to see you back Matt! Radiator cap? Had a PT Cruiser do this... Drove me NUTS until I got a lucky guess. I have a similar issue with my Subaru. Passes ALL tests, but boils over on a hill climb. I KNOW a head gasket is blown, but CAN NOT for the life of me, pinpoint where.
There is an apparatus which tests gases from the expansion tank to see if there are head gasket leaks..i think it tests for CO2 or NOx coming from combustion Could that be used to test it in that case? Also may check for blocked valves et which prevent pressure from being released into the expansion tank
I know hindsight can be a bitch... but I would’ve never removed the intake manifold. Based on the facts and evidence provided in the beginning of the episode, I to quickly deduced that a head gasket was leaking; and a cylinder was pressurizing the coolant system. My first weapon of choice would’ve been a “Combustion Leak Detector”. It’s a water bong you put in place of a radiator cap, the water inside the bong reacts to exhaust gasses. Depending on the size of the leak, This test can sometimes take 30 minutes to produce results.
I did the combustion leak tester. it was negative. plus at 30 minutes it’s quicker to just remove the intake if I have to wait that long especially for a test that has such a high failure rate as the block tester does.
@@SchrodingersBox Understood As a flag tech I’m jumping between two or three cars; so letting a combustion leak tester run for 30-40 while I do something else is a good strategy. Right now I’m doing a parasitic draw test on a brand new car while cooking BBQ for the shop.
@@SchrodingersBox There is another possibility. Instead of overpressure, it may have no pressure. Probably would not notice it with the car running, but when the car is shut off, the residual heat of the engine would boil the coolant since unpressurized 50-50 coolant boils at 226F. That can't be good for the cooling system. There may have been nothing wrong with your adapter and the reservoir requires replacement.
@@SchrodingersBox I have a question. Is EGR stuck open What do I see in long term and short term And what if it's closed and doesn't work? What do I see in long term and short term
So I have played with this in the past because it was always inconsistent and what I found is it depends if the car uses a MAF or only the MAP. if the car uses only a MAP ( speed density design) then a stuck open EGR causes a rich condition. but if car uses a MAF then it causes a leak condition. reverse is true if EGR valve stuck closed. this is what I have found at least.
Hahahaha. I always wanted a television in my garage so I mounted one but it also connects to my computer so I can see live outputs for diagnostics without having to have the computer precariously balancing on the engine bay!
possible it’s fuel leaking into cylinder. that causes white smoke too. if it’s coolant though, I have seen very small leaks where the coolant leaks into cylinder overnight and you first get some steam or a hard start after it sits. this can be found by pulling the plugs and you will see coolant spray from the cylinder with the leak.
Sir I am junior technician.now i want to work with you sir.because your diagnosing skill levels are very impressed me sir.i am alltime use your FASTTEC method to diagnosing the problems.your doing very good job for young technicians to grove sir.
I had a similar case with my car. Bad radiator: replaced. Bad hoses and water pump: replaced. But still losing coolant. We (a mechanic and i) did a compression test and all normal. The mechanic after chasing ghosts for a while he said to me "I bet you anything it is a blown head gasket, Im gonna open this thing, if is not, no charge" and was right. The head gasket had a tiny little crack, and there was no sing of water in the oil or white smoke on the exhaust, but was leaking coolant to the cilinders. And he did all the proper testing on the cilinders. Great video as always Matt. Cheers.
Lucky owner of that Honda.. quick diagnosis & free labor.. awesome video!
Ooh something to watch at almost 2am. Love it!
One of the hardest things for some people is to change their plan of attack when it's not working out. Many (most?) would attempt to make the "facts" fit their hypothesis (and then fired the parts cannon in the general vicinity of the engine bay) instead of acknowledging that they may have been on the wrong track. Glad you're not one. Cheers, Matt. :-)
I once had this same exact disappearing act with the coolant no visual puddles and all the previous tests you did I did I couldn't find it Until I overpressurized the system and discovered it was an oem hose clamp that had been cracked. This broken clamp was the find and fix. Mighty Max has a pressurised kit that comes with a way to test the cap as well. So my 2 cents is do another pressurise test but go over what the cap psi is telling you the Max is .that's how I found where the leak was. The oem clamp was half broke, just tight enough to keep fluid in but not tight enough to stop boil over.
I know how this feels...do all the right tests and no dice. I’ll be watching for the epic conclusion of the 2 Leaks, One guy Saga.
Dear Eng. Mat, I did not see your entire movie as I needed to do something else, but I thought to inform you that sometimes a heater core could leak a very tiny amount, where in some instances you could find out if you operate the heater and put the air dial on front windshield where you can notice a little bit of fog being emitted at the windshield. Also you might be able to smell an ugly odor under the dash toward the center console. You have to figure out how to air pressure test the heater core after disconnecting the inlet and outlet of the heater core preferably from the engine and not from the back panel so as to enable you to block one side and air pressure test the other with a gauge and hold it for few minutes, noting that heater cores do sustain pressure maybe up to 20 PSI or it can burst, so maybe 10 PSI is enough (investigate this before commencing), I believe you said that the water pump was replaced, and as you may know that most water pumps have a sort of pee hole that only slightly drip when hot and due to heat the dripped coolant drops might vaporize before being catched on either the floor or any panel beneath, so maybe if the heater core is checked okay to investigate that possibility. Advise the client to keep a distilled water gallon at the back of the car, and every morning before he start the car to check the coolant level and top it if needed. also if he work for 8 hours and before he start the car to get back home to check the level too. This at least for few days to build an estimation as of how much the amount of coolant loss. Take Care and enjoy your time. John Jack Kaplanian from Jordan / Middle East.
A good thought however a leaking heater core would be evidenced with the decay test. The decay test was absolutely negative with not even 1PSI drop in 5 minutes.
As always thank you for taking us along on this repair, I will wait for part two to resolve this leaking mystery!!
Thanks for watching!
Was really a puddle of water from the a.c.
Good on you for not charging for the simple rad swap. That says a lot about your character and will no doubt pay off in the future through more sales from your loyal customers, not to mention referrals. I like how you diagnose issues to save the customer money.
Build pressure in the coolant system and check that the max is correct as stated at the cap, that the max pressure is maintained. One possibility could be a jammed rusted cap that allows the pressure to go beyond the max pressure. Nice video!!
Awesome video Matt, I always learn something from you videos sir.
Awesome! Thank you!
Something "similar" happened to my dad's xterra. He wanted to change the water pump. I did several test and discovered the radiator was clogged, increasing the pressure and the weakest link started to leak one by one. The car was having a stroke. Anyways I just wanted to say Thanks for your teachings. I've learned a lot from your videos.
Another great video Matt. A new Schrodingers Box video always feels a bit like a childhood Christmas...
I was really looking forward to another upload! Thanks Matt.
At the moment I am chasing down an issue on my bmw n47 Diesel. It used to idle rough once the engine reached operating temperature.(misfire like symptoms)
Th mass air flow values I got from my obd scanner didn’t seem very consistent. That’s why tried being a parts changer(shame on me) and installed a new maf. Testing the maf was outbid reach for me because I would’ve needed an oscilloscope.
Th issue was instantly gone after that and stayed away for half a year. Now the same symptoms still sporadically appear.
The next step for me whould be to assamble an injector testing kit, which compares the amount of fuel which every injector sends back. It seems like one of the injectors seems to be working okay ish but not perfectly.
For now I’m using liquy moly diesel fuel system cleaner with every filling of the tank. That solved the issue short term.
The funny thing is I only got one code while these symptoms appeared which was indicating a rich fuel-air mixture. (Didn’t always appear together with the symptoms) (yes, the car has a broadband oxygen sensor)
If you don’t have time to answer this long comment, don’t bother. I just wanted to share what I’m doing. :)
Best regards from Berlin :)
Hello mr. I like how you explain and solve problems, thanks so much, greethings from baja south mexico
When the question was first asked my guess was the timing chain cover gasket. However with all the negative pressure tests and no evidence of coolant on the ground I’m stumped too, will be following this for sure.
Hi Matt, A suggestion have you checked the Welch plug on the block for pinhole leaks? Keep the good work up.
Bore scope to check for a steam blasted compression chamber due to cracked head.
lol seeing him lost was worth it! These are so trick to do sometimes well pleased so far.
I agree, the next step should be to confirm the coolant leak, it might be that the puddle under the car that the customer sees isn't actually coolant.
Also, if you suspect high cooling system pressures is causing components to fail then you could measure the coolant pressure directly during normal operation, just attach your coolant adapter and take it for a drive. If you see high pressure, then would be the time to find where its coming from. Like you said, it might be that the head gasket only leaks when up to temp?
Matt, you will be AWESOME always in my book brother and thanks for showing all this really interesting problem hope will be another video to see what is the problem 100% and thanks for sharing.
Matt, Have you considered a first look type pulse sensor and scope on the coolant tank with engine running? You can make one for about £5 or buy one ready made. It will detect very small pulses in the sealed coolant system, you can even set a channel on scope for cylinder reference
A $50 combustion leak analyzer is quick and save a lot of time, i've found them very useful.
Yep I used it on the first diagnosis- it showed negative.
Three bay garage is very nice! Through testing Matt as always. Great case study!
A sticking thermostat will cause inadequate cooling and overpressure with secondary leaking. Some have a second valve that allows coolant to bypass the radiator when cool. It is not an easy diagnosis without real time cooling system pressure measurement, so many would just swap the thermostat. Perhaps it was replaced with the water pump?
I had a bad head gasket in my 2005 Altima and I looked in the spark plug holes with an inspection camera. Nice shiny piston gave it away. An intake coolant leak will show the same. If enough liquid enters the cylinder you can get hydrolock. Some liquid could give a hard start due to high compression.
I noticed sometimes that a slightly stuck closed thermostat causes these same situation from pressure and to overheating
Interesting note... sometimes there can be diferent water pumps with diferent flow. I know in the cummins world there a bunch of diferent ones that will fit but a 4bt pump will be lower flow than a 6bt or 24v. Sometimes guys actually trim the pumps on high rpm 24v cummins builds because they will over pressure and blow the frost plugs out.
The ole rubber glove on the radiator cap hole may have worked here.
After that Toyota which passed all the head gasket tests (leak down test, compression test, and coolant chemical test), I always second guess head gasket tests now. Im traumatized now lol. I had to use the camera to look inside the cylinder and see the coolant inside the cylinder after sitting overnight.
LED light rod? Honestly, Matt how could you be so naive? You've paid $200 for a lightsaber! On the plus side, I've heard you can use lightsabers to seal head gaskets.
Seriously though, it's great to see you back in the saddle again, man; UA-cam hasn't been the same the last couple of months.
hahaha thanks Andy!!
I was relieved to see this was not going to be an electrical issue video because I’m still trying to get my head around the basics of that area. Then I realized this also looks like it’s gonna be tricky, even though I understand everything involved. Two potential areas of solution occur to me. The first is more basic than anything you covered, Matt. That is to confirm customer complaint first before moving on to any diagnosis. I don’t think you personally confirmed the complaint (for whatever reason) and you may be chasing your tail for the wrong reason (heater/AC, other). The second is potential water jacket blockage within the block. Similar to pressure cap malfunctioning, perhaps this might cause an overpressure condition. Pure speculation on my part as a total novice. Too bad some viewers don’t pay closer attention to your entire video, as at least two suggested chem test which you clearly listed as having done previously off-camera (but definitely something I was going to suggest until I saw it listed). Can’t wait for Part 2! Oh, if all else fails, then what’s left is what initially seemed implausible - a major set of coincidences. 😉🔧🧰
Not sure if you mentioned the year of the car, but It appears to be 2005-2009? ITs 10-15 years old, plastic/rubber is just plain worn out. The water pump is replaced, up to full snuff and working as it should putting strain on an old system is a variable. Another variable is pressure cap not venting properly and over pressurizing not letting coolant in/out of the Degas bottle.
Try it with a 4 gas analyzer
Engine warm and measure for higher HC % in the coolant reservoir
if only I had one! good thought though!
Scanner danner, does this,. I liked it.... Cheers heads up
I'm still with you on the leaking head gasket. Did you take off the thermostat during the leak down test? Engine cold during leak down test and it would have closed yes? That's why no there were bubbles coming out of expansion tank
At the beginning, I thought you were gonna say it was just old, deteriorated hoses..
Been a bit, happy you posted. thought the coof got you or something ; P
On my Honda Civic.-Compression test was good but it kept blowing hoses/rad. Actually measured CO at radiator with a gas detector.(Got ther idea from your video with CO2 detection) Car is functioning with stop leak and new radiator for now. Have to add coolant every 75 miles
I wonder if there is a way you can check the pressure in the coolant system to validate your suspicion that the coolant system is being over-pressurized? However unlikely it may be, it's always possible that these series of failures were just a coincidence.
there is. you simply leave the pressure tester on while running engine and it will show the running pressure.
I'm sure someone has mentioned using an exhaust gas analyzer in the overflow tank. If not it's a great option.
Customer stated it didn't get too hot. The melted timing cover says maybe it did.
I am thinking coolant leak in intake manifold to exhaust port. Only shows when the car is warmed up to temp. How about compressed air at the tail pipe and look for bubbles in the coolant reservoir or in oil? Note: Im not a Mechanic but I do own a Buick.
The title is not entirely true, you're two guys at the car! As long as it's a family friendly video happy about that!
Even if it's not the head gasket, the previous symptoms do suggest an over-pressurisation of the coolant system. Keep looking.
exactly!!!
Is there a way you can test the expansion tank pressure cap to make sure it is working and not overpressuring the coolant system
i was just about to suggest the same, although I think Matt would've probably went over it the first time he had the car
EDIT: scratch that, the new radiator came with a new cap.
Since when?
Beat me to it. I would suggest testing it with more than one style of cap tester too.
There's a cap tester that goes to the pressure tester you currently have that requires you to screw it in and there's also another style that's included in the pressure test kit at Autozone that you push in to the pressure tester in the kit.
I would try both types since I got more consistent results with the one in the Autozone kit. The other style just showed caps I knew were bad as completely fine.
i used a coolant cap with a bicycle valve put in and perfectly fitted with no leaks and pumped the bike tire pump to pressurize my system it worked well :D
oops i misread what you said. idk how to do that fella id buy another cap hahaha!
From 11:10 you talk about your suspicion, that the car has a head gasket failure and that's causing the leak. This might be the case (haven't finished the video yet), BUT I want to share my experience with old cooling systems at this point:
- My 2001 BMW E46 with now nearly 260.000km started developing coolant leaks about 10.000km ago. First the water flange at the rear of the engine towards the cabin heater got leaky because of a brittle O-ring (10.000km ago, a typical problem). Then a couple of months ago the radiator started leaking because the aluminium corroded too much (also a common problem, you can see the coolant passages swell, sometimes the passages even delaminate from the fins and start to bow down!). While fixing the radiator, I noticed that the plastic connector of a hose had a spot where the plastic got brittle and leaked. This seems to be a common issue as well.
BMW claims that the coolant is good for the vehicle lifetime and does not need to be changed. At the first major leakage, the coolant was changed though because every shop (later I did the repairs myself) filled it with a different coolant, resulting in a nice, brown colored coolant..
- My first and second 1994 Honda NTV650 had a similar story. There were small leaks when I got the bikes and after changing the coolant, there were even more leaks. I went ahead and changed every rubber seal because ALL of them were hard and brittle. Both bikes had brown or grey, fishy smelling coolant in their systems.
-> On the Honda NTV forum I created a list with all necessary seals because many other owners had similar experiences.
- Similar story with my 1984 Honda VF750F, started leaking after changing the oooold coolant.
=> Some manufacturers claim that coolant does not need to be changed but I find that this is not true. All the vehicles with improper cooling system maintenance had issues with brittle seals and after fixing one leak, another one is not unlikely to occur. Sometimes a coolant change or filling up coolant can trigger that as well.
I learned (and still do!) a lot from your videos and as a fellow researcher, I believe that a big part of Science is learning from each other and bouncing ideas back and forth. So I don't want to say that you're wrong but just share my experience for consideration :)
Just trying to help .... something to condenser ! trying to find a head gasket leak with either a in cylinder leak test or relative compression test is unreliable .. compression when cranking will be at the most 200psi cylinder leak test is only 100 to 150psi depending on the compressor ... BUT when the combustion gasses are ignited cylinder pressure can reach as high as 1800psi ... so if the leak happens at 300 psi you will never find it ..... chemical annalists of the vapour above the coolant is probably the best way .... you could also monitor the pressure build up in the cooling system if it exceeds the pressure cap rating that would be of concern Best regards JF
Changing coolant in an old cooling system some times cleans the internals and cause leaks.
In this situation the pressure cap should always be tested
I have a blown head gasket pressurising my cooling system at high operating temperatures (bubbles observable).
Its my only car and I'm not in a position to repair it or buy another car.
I re-routed the fan relay grounds from the ECU to two rocker switches beside me in the centre console.
I maintain the engine temperature manually (risky I know) and no more leaks.
Granted, now my ECU doesnt know when the fans are on and it won't compensate with IAC but I keep an eye on the idle speed and the oil pressure.
I think you should let this car get hot and see how it behaves.
Heat, as I'm sure you're aware, will cause dimension change in the head, the block, and the head bolts, and may be relieving head gasket clamping force.
Like another person commented, it could be a radiator cap stuck closed and over pressurizing the cooling system. I think this may or may not be detected by by a pressure decay test as it could be leaking under a pressure higher than the standard testing pressure
yes but there is a new cap with the new radiator.
I think your mistake was focusing too much on head gasket problem. These kind of problems are frustrating I know that for a fact. I hope this mystery resolves and does not cost a lot.
How the heck did I miss this 2 part masterpiece? Was this title a one off from 2 girls 1 cup? 😂😂😂😂💩💩💩💩 alright I'm done clowning, let me watch this and try to get this pea brain of mine to learn more from such a great teacher!
Lol thanks man. Yeah this is a good one- it’s a good lesson to just stay on objective data and not be swayed by your intuitions.
Hi,thanks for the videos you sharing to us. I will suggest you to try the combustion gas leak tester, the one with the blue fluid,which when detect gas,react ,and turning to yellow.
It's working very good, and of course, it's a time saver, specially for this type of engines, which involve a lot of work to test for head gasket. maximum in 5 minutes ,you know if you have head gasket. you just remove the radiator cap, to test the system. nothing else.
I did do that first. it was negative. will show that next time.
The lower intake manifold cracked and it’s burning off into the exhaust
good thought!
I know I’ve had that issue with a lot of chevy’s
Pontiacs too especially around 2002-20010
Oh a cliffhanger! Hey Matt let me know when you are in PA again for work. I'll meet ya for lunch. I am buying!
I’ll bring the beers.... 🍻
time for the old paper test to make a return? maybe try the rubber stopper test even though the stant tool came up negative?
5 minutes to midnight...but tomorrow is a paid holiday for me...so yup...watching 😎
You know Memorial Day isn’t til next week I hope lol.
A week from now is the holiday bro
@@GlycerinZ Not in Canada
@@remodz6385 Today is Victoria Day in Canada
Interesting problem !!
Bet money jiffy lube screwed up, almost certain without even knowing. Radiator cap not releasing pressure or someone used distilled water eating the metal of its minerals causing failures.
Monitor coolant pressure with engine running while watching temperature. Combustion pressure is 10x what you were testing with. Have seen videos where they use a pressure transducer on the cooling system....expensive tools. Not sure what the chemical test you used checked for...carbonic acid? Not good if coolant is getting into the cat.
I watched this video with much interest as unfortunately I have a 2013 Ford Escape (first owner) with 130,000km (Canada). My coworker blew her engine at 140,000km on the same model due to the notorious coolant-leak-into-cylinder-chamber issue on these models. I am expecting my engine to blow as well in the next year or so. It seems the money required to fix this issue is not warranted considering all the other issues this car has developed since new.
Regardless, the cause you tracked (blown head gasket) was my first guess considering the history of these cars. Considering you haven’t been able to prove this is the cause, could it be a plugged rad or cooling jackets that is leading to higher pressure in the upstream cooling components, including like you observed, the pump (highest pressure), then the hoses?
Is the right coolant being used? Is the thermostat stuck, or a fan problem?
Much better than "two girls, one cup!" 🤢
either way I am eating sh1t hahahaha
Could it be that the system was not properly bled of air when the radiator was replaced, and it isn't really leaking, just burping out the air as it runs? Just asking, I am not a mechanic.
that was ruled out with pressure decay test.
@@SchrodingersBox I don't understand your answer. If there are no leaks, it would pass the decay test, but the coolant level would drop as trapped air was worked out. Obviously if the coolant loss continues, that's not it.
it’s because the issue with coolant loss happened even after I did the pressure decay test.
the pressurization of the system would remove any air pockets if they existed.
could have been air in the system from the last repair? or the obvious bad radiator cap? test that yet?
Sounds like my POS Ranger. Alum Heads on Iron Block no bueno. Heater core went, then Radiator went, heater core with radiator went this time huge cloud of steam out the tail pipe. Cracked heads, new long block, just doesnt run right compared to other trucks money low mile pit.
Why not start with a chem test?
What if you have a thermostat sticking ever so slightly? Doesn't make much sense if the car does not overheat but worth checking. Does the car overheat or just loses coolant?
I would first have try the combustion leak tester with fluid. What are your thoughts on using this test???
i use it all the time and it was first test i did. it was negative.
Chemical test...... nevermind.. lol
Hahahaha yeah it was actually the first test I did a month ago, I forgot about it but it was negative,
@@SchrodingersBox that leaves sizzle and heater core. Ez yest if you got time and good weather is to bypass the core fore awhile and see if leak stops. Good puzzler tho. 👍
Thermal expansion of dissimilar metals, e.g cast block, aluminium heads etc once heated and expansion has taken place, OEM composite gaskets can't make up the variance of the dissimilar metals seperating. Definitely head gasket or intake leak. Will only show itself at operating temp or above. Most likely excessive air in the system over pressurising the cooling system which causes further detriment to the already compromised gaskets clamping force.
not sure what evidence you are seeing for any kind of head gasket issue. all evidence shows negative.
Merely my theory. Unsure of the particular engine's metallurgy as I'm from Australia, don't have them here. However we have the 3800 Buick which is all cast besides the aluminium intake manifold. Have had the case above where my intake manifold gasket was compromised but only after the engine was warm, the aluminium expands, cast does, but not comparatively. Had a coolant leak into the combustion chamber, O2's pick up on the variance, start over fueling and bam your Catalytic converters are dead.
I got a off the wall question for you. Do you have a business setup or anything of that nature or is just drop it off and I charge X amount per hour plus parts?
no business setup. no fixed hourly rate. just kind of wing it. more of a hobby than a business. but I do bring in more than enough to live off of.
Great job again Matt, keep up =)
Always!
Well hello there, where have you been 🤣 long time no video. I’d be very suspicious of the two cylinders that were side by side and 10 psi lower than the others.
mmmmm good observation. I should check to see if there is leakdown between them for sure.
Has the expansion tank got a hairline crack in it that is opening when hot only company has a lorry doing this garage could. Not find a leak, I told them it’s was this months before as when engine overheated the water was under tank and on top of engine
That’s a puzzling one Matt! I’m not sure where I’d go from there? 😂 I’d be suspicious of the coolant cap because you remove that from testing when you use the pressure tester. Is it running hot or overheating? Would that cause it to consume more coolant? I hope you update us lol it will drive me nuts 😉😂😂
yes indeed- coolant cap was not tested but I have ways to do that
probably there's a blockage in the radiator core.
but it’s a new radiator remember.
@@SchrodingersBox oh so sorry I missed that info 😁
Nice to see you back Matt!
Radiator cap? Had a PT Cruiser do this... Drove me NUTS until I got a lucky guess.
I have a similar issue with my Subaru. Passes ALL tests, but boils over on a hill climb. I KNOW a head gasket is blown, but CAN NOT for the life of me, pinpoint where.
thermostat stuck closed?
There is an apparatus which tests gases from the expansion tank to see if there are head gasket leaks..i think it tests for CO2 or NOx coming from combustion Could that be used to test it in that case? Also may check for blocked valves et which prevent pressure from being released into the expansion tank
yes that’s the chemical test I used.
That's the chemical test (looks for hydrocarbons in the water)
Need a mechanic like you would like to be a customer
eh no offense i love your info but couldnt you just put a regulator behind the air nozzle and just pressurize at 15 psi opposed to whatever??
I know hindsight can be a bitch... but I would’ve never removed the intake manifold.
Based on the facts and evidence provided in the beginning of the episode, I to quickly deduced that a head gasket was leaking; and a cylinder was pressurizing the coolant system.
My first weapon of choice would’ve been a “Combustion Leak Detector”. It’s a water bong you put in place of a radiator cap, the water inside the bong reacts to exhaust gasses.
Depending on the size of the leak, This test can sometimes take 30 minutes to produce results.
I did the combustion leak tester. it was negative. plus at 30 minutes it’s quicker to just remove the intake if I have to wait that long especially for a test that has such a high failure rate as the block tester does.
@@SchrodingersBox
Understood
As a flag tech I’m jumping between two or three cars; so letting a combustion leak tester run for 30-40 while I do something else is a good strategy.
Right now I’m doing a parasitic draw test on a brand new car while cooking BBQ for the shop.
Could it be a stubborn, and inconsistent thermostat? If it intermittently stays closed wouldn't that pressurize the system?
possible. pretty much any variable other than head gasket would be suspect.
i will take a guess that the head gasket is leaking from one coolant chamber into another ?
hmmm is an interesting thought. but if that is so how is pressure increasing to force leaks?
I’m not a mechanic nor do I pretended to be one. Could the thermostat be sticking?
thermostats almost always stick open but it’s a thought- will check that!
You likely have the wrong radiator cap for that radiator. No matter how the pressure is created, the cap should relieve it after 16psi.
new radiator has new cap though.
@@SchrodingersBox Just because it fits doesn't mean it is correct. There are different depths for the same style cap.
it’s a 16 PSI cap and the gasket seals the neck and would clearly release to the overflow.
@@SchrodingersBox There is another possibility. Instead of overpressure, it may have no pressure. Probably would not notice it with the car running, but when the car is shut off, the residual heat of the engine would boil the coolant since unpressurized 50-50 coolant boils at 226F. That can't be good for the cooling system. There may have been nothing wrong with your adapter and the reservoir requires replacement.
Nice new diags ! I think I have a problem on the paid channel, what was the last video you updated on it ? Thanks a lot again Matt !
last video on pay channel was the network diagnostics series.
@@SchrodingersBox thanks a lot I was thinking I was having a problem refreshing the page
yes I found you do have to refresh the page occasionally- i cant log in unless I do that for some reason
Thank you I Love your channel
Your explanation is special.
Thank you! 😃 You sure got first comment with the quickness!!
@@SchrodingersBox
i was following explanations from four continuous hours
I have two phones🤗
@@SchrodingersBox
I have a question.
Is EGR stuck open
What do I see in long term and short term
And what if it's closed and doesn't work?
What do I see in long term and short term
So I have played with this in the past because it was always inconsistent and what I found is it depends if the car uses a MAF or only the MAP.
if the car uses only a MAP ( speed density design) then a stuck open EGR causes a rich condition. but if car uses a MAF then it causes a leak condition. reverse is true if EGR valve stuck closed.
this is what I have found at least.
@@SchrodingersBox
Thanks for explain ❤️
How about a chemical test on the coolant?
Yes good thought. we did that previously but it was negative- not shown in the video.
Matt, I'm intrigued: What is that wall-mounted monitor for? I'm really envious... but I don't know why. lol
Hahahaha. I always wanted a television in my garage so I mounted one but it also connects to my computer so I can see live outputs for diagnostics without having to have the computer precariously balancing on the engine bay!
@@SchrodingersBox Ok, I'm still really envious... and now I DO know why. lol Enjoy it! 😎
Could it be the radiator cap sticking, building up too much pressure? or a small crack in the plastic over flow tank?
new radiator cap with new radiator. no crack on overflow because decay test was negative.
Bad radiator cap.... Could cause excessive leaks
Why didnt run block test to check for exhaust gasses in coolant? Thats first test fot headngaskets
I did. it was negative.
"The Lab"? I that your main job, if so what do you do there?
yes my main job used to be a molecular biologist. I was curing cancer and stuff. but I am now in the corporate world though.
@@SchrodingersBox Well thanks for your work on the greater good! Do you do consulting now and shop work when available?
Is there a different smell in car , leaking heater inside cab. Carpet will be damp.
Good thinking. Nope, none of the above.
My car start white smoke but I can not find leaking anywhere I'm not sure about it .can you telling me what wrong with my vehicle?
possible it’s fuel leaking into cylinder. that causes white smoke too. if it’s coolant though, I have seen very small leaks where the coolant leaks into cylinder overnight and you first get some steam or a hard start after it sits. this can be found by pulling the plugs and you will see coolant spray from the cylinder with the leak.
check the heater core
ah yes I did- no evidence heater core leak (wet carpets etc) plus remember decay test was negative.