How To Perform A Leak Down Test - EricTheCarGuy
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- Опубліковано 7 лют 2025
- How To Perform A Leak Down Test - EricTheCarGuy
www.ericthecarg...
At long last I was finally able to put up a leak down test video for you and the really good news is that I will be replacing the engine in this truck and I hope to shoot some video of the process, I also hope to be able to take apart the old engine to examine the fault that caused the excessive compression loss in this engine so keep your eyes out for that.
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Due to factors beyond the control of EricTheCarGuy, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. EricTheCarGuy assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. EricTheCarGuy recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of EricTheCarGuy, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not EricTheCarGuy.
I wrench professionally and your videos always have something new I didn't know before. Thanks for all the useful info and keep up the good work!
Well, I used your method, and wouldn't you know it, it worked incredibly well. Pumped in shop air, and heard hissing coming from my exhaust. Relieved it wasn't the rings. Anyway, tore apart the engine, and found a badly burned up exhaust valve (among other bad things the previous owner did to this car). Just got the heads back today and hopefully it'll be up and running tomorrow.
Just wanted to say thanks for making these videos. They have been a BIG help, and I highly appreciate it.
Josh.
Your videos are excellent, Eric. I just don't know what to say anymore. My bike (a 1990 Kawa ZX10) suddenly lost compression on the highway a couple of weeks ago and I made it home at 40mph leaking oil and producing white smoke from the exhaust. So now I'm gonna have to open my engine up and do a complete check. You know, valves, piston, gaskets and everything. I am so happy I found your channel and I cannot thank you enough for helping people out. You sir are a life saver and a hero in my book!
My daughter and I are restoring an '85 Fiat Spyder. It hasn't been run in 7 years so once we get it started, these are exactly the tests I told her we'd be performing. She now understands what's going on. We both look forward to watching more of your videos. Thanks for the education!!!!
Eric, Gm trucks have a service position for the hood.Take out the hood bolts where it hinges. You will see another hole for the bolt a few inches apart from where you removed it when you raise the hood to 90 degrees. Install the bolt. Lots of room to work.
Eric, I grew up as a kid doing shade tree mechanics on old cars. Turned 18 and joined the Air Force spent 34 years active and civilian did very little vehicle maintenance during that time and I was an aircraft mechanic. When I retired I started doing little projects here and there on vehicles and work to restore a square body 1998 K2500 now for myself. When I have an issue I always check with you first. I want to say a very greatful thank you for all the help you videos have provided me. You do some very detailed and professional videos with detail with explanation that even this old turd can follow. Thanks for all your help. Jimmy
It amazes me how i can watch an almost 30 minute video straight thru, great videos man, keep it up.
@mechretired You do realize that you don't really need the tool, in fact the only reason I bought this tool was to show one in this video. If your to a point where you have a major compression leak like in this video there is only one question to answer in my opinion, "is it coming out the top of the bottom of the engine", how much is leaking is irrelevant in my opinion because lets be honest you really won't know anything for certain till you get the engine apart. Thanks for the comments.
Another good and comfortable way to find top dead center is by using the oil dip stick. Since its long and flexible, you have much more dexterity and leverage while you turn the engine. Still, good informative video!
Thank you very much for your videos. A local Pep Boys here in El Paso Texas, diagnosed my 2002 Galant 2.4l DE with a bad valve(s) because my engine was rough. Based on their diagnosis, I bought new valves & stems, head gasket kit, both timing belts, both accessory belts, and a water-pump. I got it reassembled and was able to start it. It has the exact same problem as it did before I spent $500 in parts, and $300 in tools. Wish I had seen your videos sooner. I suspect bad piston rings.
Thank you for the useful video. As for why you weren't hearing the air on the 100% leaking cylinder, the tester was down to 8psi and with a large leak, the air wasn't restricted enough to hiss. It's just like blowing through a straw or breathing normally. Next time, rather than going through the hassle of modifying the compression tester, try turning up the pressure on the leak down tester until there is enough flow that the large leak hisses.
Perfect. Good explanation, good suggestion.
As a college student I drove a ‘67 Triumph Spitfire. Fun little car. It had the Best hood. When you opened the 2 latches the Entire Hood lifted up to vertical on the front hinges. You had Easy access to the entire engine. So sweet 😎. Never seen anyone else do this.
I made my own leakdown gauge out of two pressure gauges (same full range), brass fittings and two needle valves and a regulator. The "percentage" leak you figure out yourself - I like it better that way, because I can look at and calculate the exact percentage. Plus, I have an extra valve, so I can shut off the input altogether to see if it will hold pressure over a period of time. The expensive tools don't tell you any more than a homemade one, and I can replace something that goes bad from the local hardware store. Good video, thanks.
I think that the problem with the HF model is the scale chart on the "leak gauge" needs modification to accept a higher line pressure.
man ive watched your videos for years on how to work on cars. and they always amazes me on how well these videos are made. thank you for helping me with my cars for all these years!! one of the best car channels on YT!!!!
The reason you were not hearing air coming out of the engine with the cylinder leakage tester, was because you had the shop air pressure regulated down to only 12-15 psi. The leakage tester shows the percentage of air leaking that is being put into the cylinder. I usually regulate the pressure to a minimum of 90 psi max 100 psi. If you regulate the pressure to that you will be able to hear where the leak is coming from. 12 - 15 psi air pressure is not enough to hear where the leak is coming from. I hope this helps.
A lot of the cheaper leak down testers when you crank them up that high their 'leakage' regulator hits the needle on the stopper below 0% long before you reach 100%, he may have been over cautious not to damage the instrument as I was when I bought mine. Was interesting though that he could hear leakage on the 2nd cylinder tested with the same psi as the 1st which you couldn't hear any... I'd hazard a guess there may be a valve at work somewhere there
He couln't hear it because the air was moving quite freely through the gap and there was not a lot of air going in. So that was just like if you exhale slowly with your mouth wide open...
That was a US General (Harbor Freight) leak down tester and the right gauge only is accurate with using about 10 psi of air. You can crank it up and see the psi on the left gauge, but the % leak gauge on the right then won't be calibrated.
@@holybritches Is there anything wrong with setting it at ~10psi (so the leak gauge reads 0%) to get the leakdown number first and then cranking it up to 100psi to hear where the leak is coming from?
@@fahrvergnuugen old video I know but that calibration thing confused me. I have a home tester. No calibration. I put whatever psi i want. Sealed outlet I get same psi on both gauges. On engine reading on right gauge goes down if flows. Difference between 2 divided by 1st is %. Funny though as I just ordered a new tester because hose to cylinder on mine was rotten. I tried one from a new compression tester and no flow. Lol as he showed on video I hadn't removed the valve stem.
It’s been 11 years since you posted this video and you were years ahead of your time then, ha! Thanks for sharing your experience and knowledge!
Awwww, Look at the baby face... I can't believe I have been watching you this long. I totaly forgot about this old shop.
I NO LONGER FEAR ENGINE MECHANICS, THIS GUY ERIC HAS GIVEN ME SOOOOOOOOO MUCH CONFIDENSE TO DO MY OWN DIAGNOSTIC CHECKS AND SAVE A PACKET OF DOSH TO! KEEP EM COMING ERIC!
Kudos!! Man, I'm a veteran mechanic of 19 years. I've done these tests myself, but its been awhile. This is a very informative and thorough video man, and very helpful as a reminder/reference even for a seasoned mechanic to remind me of what I'm looking for. Kudos man...
Actually, since I knew I had a compression problem anyway, I did Eric's "modified" compression tester trick and I heard air rushing out of my exhaust with the piston at the top of its compression stroke. My exhaust valve was pretty burnt up. It's all fixed now. BIG thanks to Eric for this video, saved me a ton of time and money!
Great video, only one thing missing: By removing the sparkplug(s) next to the bad cylinder and air comes out through any of them it can be a cracked head or the headgasket between two cylinders.
Watching this again many years later...
One other easy way to determine the compression stroke is to use an endoscope or borescope to watch the movement of the valves within the cylinder.
I appreciate and gain confidence in what you tell us through your honesty and openness about what you're doing, your observations, etc. Thanks big guy.
May/31/2021,
@ Erick the car guy, can't thank you enough, years pass your info and videos are priceless, thnk you Sr.!
Your problem is in the way you set the regulator on the leak down tester. Always set it in the increasing direction. When you backed it off you should have gone down much below your target and then come back up to the target pressure.
The way you did it would have set your pressure much lower than you saw on the indicator, maybe even near zero.
That's what I was thinking when I saw this! 17:00 After he locks it in place you can still see the gauge moving so it already had a leak before connecting it to the cylinder? Sometimes it's the operator not the tool...
I was thinking too but he rechecked his tool onto different cylinder just like before
Nicholas - agree. When I worked in a high pressure/temp processing lab, we ALWAYS backed off a regulator setting from set point that we've gone over, then slowly came up to the set point again. The mechanics of the regulator are the same as anything that has "backlash". And ALWAYS tap the (mechanical) gauges. They all stick to some degree.
The guy wears a helmet while he bikes. Trust him
@@AZStarYT oil filled gauges aren't prone to sticking. I know they're not commonly used. But I have for years.
@EricTheCarGuy I use the HF leak down tester as well. After you use it to measure the leakage you need to open the regulator more to allow more air to flow through the gauge into the cylinder. It is just like the regulator on a compressor, when it is set real low to 18-20PSI, almost no air is going into the cylinder. So you have to open the regulator once you know there is a large amount of leakage to let enough air through to hear where it is coming from.
I may have an even poorer man's alternative to the leak down tester. A neighbor had a Silverado with a 4.3. He had attempted to change the cap and rotor and broke off the torx screw that held the cap to the body. He pulled the distributor and drilled out the bolt and retapped the distributor body and he once repaired it, could not get the distributor to drop back in time. He came to my drive asking for help: As I listened to his tale it became clear he had not timed the engine before pulling the distributor I scratched my head and told him to follow me. You should have seen the look on his face when I handed him my shop vac and a cord and got myself a ratchet and socket rack and a roll of Gorilla tape. While he hooked up the vacuum to power I pulled the #1 plug and turned the timing mark around to TDC on number one. to verify that i was not on the exhaust stroke, I pulled the number one plug and hooked the vacuum hose to the EXHAUST port of my shop vac as a look of regret that he had involved me crossed his face. I took the vac to the back of the truck and affixed it to the tail pipe using the gorilla tape. Pretty much as soon as I turned the vacuum on, it blew its own hose out of the tailpipe proving that the valves were closed and it was on number one TDC. He though, was unsure of what the flying hose meant, and what I was doing and I could feel his questions coming. I put my finger to my lips and motioned him forward and just for kicks I turned the crank another turn and had him retape the hose and turn it back on. The hose stayed attached to the pipe. I then brought him to the front driver's side plug hole to feel the rush of air coming from the plug hole. I then explained the 2:1 ratio between the crank and cam and told him just because a piston was up did not mean it was on the compression stroke. you could see him chewing on it as I put it back at TDC and aligned the oil pump rod. I think something of a dim light began to form in his eyes as the distributor body finally dropped to the block. The following day I came home from work to find a gift at the door with an envelope on it. in the envelope was a card that said I thought you could use this. I ripped off the paper to find a plain cardboard box with writing in Magic Marker that said "JIFFYFIX VACUUM CLEANER ATTACHMENTS". I opened the box to find a set of Exhaust pipe reducers that when stacked up could adapt my Vac hose to up to a 3" pipe. Chuckling, I put the box in the bottom of my Roll away next to an identical box in the identical handwriting that read BLOCK UNLOCK TIMING CLOCK. The story of that box is for when you do the video on Frozen engines.
Thrre's more than 1 ex valve open at a time, wouldn't the vac blow thru another, if you had an ex leak wouldn't it just go there instead.... have you been watching cartoons?
I like the way you think. Many years ago I took an air regulator, gauge, and a few fittings and made an air source I could regulate for painting and found it also worked well for pressure testing the crankcases on two cycle snowmobile engines. So it should do as well to do leak down tests. Great video..I once had a guy I worked for tell me it wasn't about how many tools in your shop but how well you used the ones you had. you remind me of me. Thanks.
Eric I love all your videos. I can relate to the basic old school testing. Been at this for 25 years and I have always learned something from you experience. I used to use tp or a rag unfortunately some motors today suck cause of there deep holes on the plugs so I use the compression hose and my thumb. Just adding a little insight for people watching your videos to help out.
many ways to skin a cat. Good thing too because there are many cats!
Eric, thank you much. I had no idea how to do a leak down test. You have excellent communication skills and now feel confident if I ever have to do a leak down test....
This dude is cool man! This video has pointed me in the right direction with my 7MGTE motor in my Supra Turbo!
Thank you for what you do here on UA-cam man! Really appreciated!
@EricTheCarGuy Problem solved I took the car to a place to where they did like you said a professional fuel injection cleaning and what a big change now. Thank you so much for all your help!!! I am happy now.
A note for the Harbor Freight shoppers regarding the leak down tester in this video. It is a low pressure tester as opposed to the higher pressure generally tested at by most with the more expensive units. Lower pressure through the same size orifice = lower air volume = less noise. Hooking it straight to shop air or using a higher pressure setting on another unit simply makes it louder. As a point of interest I think the microphone was more sensitive than the ears because I thought I heard the sound come through on the video briefly at the appropriate time the first time through before the shop air was hooked up though it was faint.
I also heard a faint noise.
🤣🤣🤣
@@rightsdontcomewithpermits7073 🤣🤣🤣
you beat me to the punch by only 7 years🤣🤣🤣
I never used a leak down test before, so I liked your explanation. I was wondering why the air pressure didn't drive the piston to the bottom of the cyclinder, but I could see you were only using 8 lbs. I think that is a very good diagnostic test. If the compression is low, you will know where the leak is. Excellent!
@1sick05srt I had the same problem with my cheep gauge as you could see in the video. I think the reason they limit the output of the tool is to prevent the engine from turing over during it's use, unfortunately this makes it so that the tool is much less accurate.
When you were screwing around with that leak-down tester, I so wish I could have told you to pull on the valve to unlock it. Glad you found it though. I just made my own tester. An old spark plug, an o-ring, 1/4" iron threaded pipe about 2" long. Busted the ceramic out of the spark plug, welded the pipe on to it, jammed a hose on the end, tighten up with a clamp, put an air coupling on the other end, and bam. I even put a cheap regulator in line. Just to make it look more professional. Now I just need some snap-on stickers and throw a couple hundred bucks out the window, and I will feel as if I just walked off the snap on truck. Lol
Great Job Eric! I like the fact that you keep it real and get the message through to us learners. Thanks for the edgamacation!
Tip - If you ever get an engine that fails both compression or and power balance tests, then you do the leak down test and you cant hear any air escaping or register a leak down, slight chance it could be a worn out cam lobe - no valve noise, no leak heard but low firing pressure and cranking pressure. - Pop the top cover the use dial gauge to make sure all the valves are opening the same distance - not common at all but sometimes cam lobes can chew out and the valve hardly opens - but no valve noise like a collapsed lifter.
Hey Eric, watching your videos to prepare for ASE tests. I'm no mechanic, but I am a carpenter and I know air compressors. If I can offer one small piece of advise is that in order to try to hear the air leak better when connected with the leakdown tester gauges, it might be easier to just turn the outlet knob of the gauges to open more and allow more air through, achieving the same result as to connecting directly to the air compressor. you may even fully open up the outlet adjuster knob and crank up the PSI at the compressor, and I guarantee you will hear it then. Thank you for all that you do, I hope I can help back just that tiny bit.
SkillPictures I am Watching trying to prepare for my ASE A-8 engine performance test. Look at Ase.com for the PDF practice tests for help. I am taking mine to help my pass my engine performance class for T-Ten even though I am going into the service side due to health issues.
SkillPictures I do not recommend turning up pressure. My tester looks just like this and based on the sticker is from a freight store in pittsburg. Actually its a replacement for the 1st one because when i turned the compressor past 90 it locked the needle to the pin and would no longer adjust. i just used it for the 1st time today and actually turned my compressor down to 80psi to protect the cheap tester and had no problems.
The best part of ETCG vids is that he walks you through the thought process.
lots of people probably know this, old skool stuff, when using the compression tester if you get a low reading at first just remove the tester add a few drops of oil and try again and if the reading comes up its the rings and or piston and if it doesn't its the valves or head gasket.
Hi, good video Eric!!
Question??
So you are saying, there is more than 1 cylinder is licking right?
Because @first you did it in the #6 and it was a little nouse, ones you did the other one, sound like is more stron the air coming up!!
So what's is going to be w/ this car?, a head gasket oe valves, or new rings, ? thank u very much for the videos u are working on, and keep up, thumbs up.✌
duggy788
Hi, i will like to ask u about you mantion, abaut the lick down test?
So if is the rings, is because is wearing out or is not in the place, because if the ring is not in place, is going to lick right? thank body for u add.
if you put few drops of oil down the spark plug hole and spin the engine with pressure gauge screwed in head, and if the pressure comes up the rings are broken or there is to much wear in cylinder, if still no pressure could be valves or gasket .
Thats where im at now looking at replacing rings on piston but i skipped the leak down test which im thinking about doing now before tearing into engine block
one of the most informative comments on youtube. thank you.
I'm going to do the leak down test by injecting air and listening as you described to determine valves or rings, what a great tip you old dog, I just learned a new tip!
"We know, we don't guess. We gather evidence" Best quote yet.
And in the end, he wound up guessing anyways
If you're not sure then you're still guessing, you gather evidence or information and come up with an educated guess if you still don't know the answer, sequence...whatever it is. Educated Guess.
We learned to do that in A&P school. Used a very similar tester too. The instructor told us alot of the same stuff you did about the air out the intake/exhaust/crankcase vent ect.
You can't hear the air rushing out because you are only putting 8psi into the cylinder. Whereas when you put in 100psi of shop air.....
Yes he is not using enough air obviously but if you use too much pressure (100psi)the engine will turn over unless the crank pulley is secured
@@kllgrogto5838 then secure the crank! it needs a good psi to make the test worthwhile
@@dopiaza2006 if you read my comment that's exactly what i said
@@kllgrogto5838 I know - I was just agreeing that without securing the crank and using decent psi, the test is worthless.
@@dopiaza2006 exactly
You were so young back then. The more I learn the more I realize I need more troubleshooting methods. Thanks
thanx Eric, i'm learning alot of things from ur videos :) and it's always interesting to watch
24:27 - 24:34 : The best mechanical quote I've heard so far. Thumbs up @EricTheCarGuy
US General. The tool is measuring the tool's leakage. LoL
Just an interesting bit of info. I am an aircraft mechanic and our "compression test" is I guess a "leak down test" in the automotive world. When we do a compression test we legally have to verify that each cylinder has a minimum compression of usually 60-65/80 depending on engine manufacturer. This requires us to always use a differential pressure tester, or a "leak down tester" to perform a compression test. These tests are required annually.
Erick I got the same tester and the way u hear what s leaking is by adding more psi to ure regulator...
Lol he didn’t have the air on at all it seemed
JUNKfindergood van I was thinking the same xD
@JUNKfindergood van how about you perve somwhere else bozo
@@jamesdean9943 this is why your still a virgin loser
😂 chasing a girl 6 years later
Hi Eric,
I just tried a leak down tester for the first time. It's not HF, but apart from the sticker it's identical. Well, I couldn't get it to work and eventually found that the tube that screws into the spark plug hole has a schrader valve in it like a compression tester! Removing this has it working OK now. This is just a tip for others that are having problems. Also if you have deep sparkplugs (OHC) be careful that the SP thread adaptor unscrews with the tube and not remain in the head like mine did. I got mine out by putting some loctite on the tube thread and reinserting it into the adaptor. Once set, it unscrewed easily. It might be best to loctite the adaptor onto the tube before you start testing.
Eric,.. What about some kind of smoker tester in the leak down test? How many miles on this truck?
TP for your bunghole,.... ahhh the 90's! I miss that decade :)
this guy is awesome! used his technique with the compression tester as a cylinder leakage tester...car wouldnt run once hooked up to air all came out of the intake with engine at TDC...proving a bad intake valve...thank you very much for the video
the 112 dislikes are from GM executives
🤣🤣🤣 that's100% accurate
Perhaps someone else mentioned this (I haven't read all comments), but the alternative to boosting the air pressure in order to spot a leak is to amplify the sound. One technique I've used very reliably for 40ish years is to listen through a piece of vacuum hose. It's like a stethescope for air. Multiple times I have quickly pinpointed soft leaks, both vacuum and exhaust, that mechanics hadn't found in hours of searching. If you haven't already, try it, you'll like it. But use clean hose... at least the end you put in your ear. :)
Eric that was exactly what I needed to know. You have made my life easier. Thanks and God bless you and your Family.
Hi Eric, thank you for a brilliant and informative video, just one or two things to add - I use a drinking straw to find tdc rather than a screw driver - if the plug hole is at an angle could
Jam. Also I made my own tester with two identical gauges and a transfer hole of 1/32" and just see / calculate the %age loss. Regarding cheap compression testers and leak down testers my take is never buy anything in one of those red blow moulded the boxes. Thanks again, Dave.
Im sure tou had the guage zero'd but no air allowed out of it into the cylinder. You never had the thing pumping air into the cylinder
James Barratt exactly what I thought. for the sound part he'd need to open the restrictive valve on the leak down tester. always great videos. keep making them & I'll keep watching.
Correct, @@stephenwgreen78. He didn't open the incoming air regulator. It was originally showing around 20 PSI, and was showing around 10 PSI on the good cylinder. Important to note here, there are indeed various different models and types of leak down testers. Some are High pressure, some others are Low pressure types. What ever type he was using, the incoming air needs to be adjusted to shop air pressure. If there is no air entering the cylinder, none can leak out. Thanks.
This is just how the HF tester works...and it works fine! You don't need to run at high pressure to get an accurate reading, in fact it can actually be more accurate running LP than HP. High Pressure will help you find/hear the source of the leak more easily however. Other testers may work at higher pressures that's all, just comes down to how their regulated/calibrated (usually dictated by the orifice diameter between the gauges inside the tool). yes, I said orifice. Great video Eric!
10:09 for difference between leak down and compression test
It boils down to volume of air to restriction ratio. No restriction/ broken rings vs a small leak at a head gasket or burnt valve. Suspected broken rings obviously "dumped" your air so quick, there was nothing left to hear.
I'm currently working on a ram 4.7 with #1 at 40psi while 3 is at140, 5 @150, and 7 @ 155.
As a bit of a gun jumper, I started the tear down. Got the intake off and valve covers. then decided to hook air up to #1 at I don't know, maybe 20-25 psi. Air gushed right at the head. Possibly into #3 as well as bad valve(s).
I suspect maybe a bent valve since 18 months ago, I replaced (4) bent intake valves on bank 2. I also suspect bad head gasket because of the obvious coolant in oil.
Good video here that provides food for thought. Thanks
ERIC THE CAR GUY you mention all ways we gone hear some noise coming out of the crank case so it's normal if I get 150 psi on my cylinder but hear a bit of hissing
EL DIESTRO DIY yes its normal in some case like yours, that do to the piston ring OEM Gap spec.just an example and I know I will judge, but the gap should always be bigger on piston rings on an engine that was made to shoot NOX, then a car to save gas for daily use. not all engines have the same ring gaps.
Yep all engines have ring gap, you can try lubricating the cylinder with a few drops of oil and a rotation or two of the crank as +duggy788 mentioned in his comment if you want to negate a lot of the blow by caused by cold start ring gaps
Eric I must say I've followed you now for some time and because of you and your videos I've become a better tech.
“TP for my bunghole?!” I died! Hahaha!
It's good to watch quality vintage content. Im here to learn the leak down test for a 1947 Ford 9N tractor that has low compression.
"I'll just use some T.P." Oh please, say T.P. for my bunghole "T.P. for my bunghole". Awesome.
Blazing Buttocks good luck finding any now. Corona virus, am I right?
@Placer No because I rotated the engine so that cylinder was at TDC (Top Dead Center) before I did the test.
you only had the PSI from your compressor side set to under 10 PSI, does it matter how much pressure you put through there to get an accurate reading?
Not really. You cannot put a lot of pressure, because the piston will go down :)
good advice man, figuring out what it is before you tear it down is critical. i worked for a old hand that did it by tearing it apart and throwing parts at i, with a 50/50 luck rate. lost alot of customers like that
Awsome video. Now I'm gonna teach my mechanic how to test my engine.
It seems you already know everything, why watch the video? Instead of trolling you should make your own "correct" leak down video. "Management at GM have a saying, If you talk the talk then walk the walk." If one were to click on your profile they would see that you have no video uploads only troll comments from someone who just discovered youtube less than a year ago. Welcome to the 21st century.
Thank you Eric for making videos, with 127,000 views they must be helpful to people.
He closes the pressure valve after setting the correct pressure which is totally wrong! You need the pressure in order to measure the leakdown percentage! Otherwise it will always go to 0% even with a minimum amount of leakage. The second tested cylinder has no leakage, the leakage occurs when connecting the hose to the meter and loses some air...
He didn't close any valve. He only locked the setting of the pressure regulator.
Thanks!!! The part where you remove the Schrader valve from the compression hose and use it for a modified leak down test tool is genius. I was able to complete a leak down teat on 2/6 cylinders before my hose wore out, but am getting a fitting this week so I can complete my leak down test with no leak down tool next weekend. The work you are doing here is important, and I appreciate it. I have a 98 honda passport that runs beautifully but has had abnormal coolant loss in the last year. Because of this leak down test I believe only the top part of my engine requires maintenance, and it's worth keeping my collector's item kicking rather than purchase a new car.
I actual have the same leak down tester and i found if you take it past the calibration zone and you back it up so it would go back to the calibration zone it actual wont work (weird) but anyhow so if you have this tool rember to turn it one way slowly untill you get there if you go past do it over otherwise the tool will do exactly this i found this out the hard way (and after about 10 mins going what the FUCK!!! )
thanks for the tip. I was gonna buy that one tomorrow after work! haha
I know you do this everyday. However, hearing some advice should never be painful. I would recommend turning the crankshaft one full turn and test Cyl-6 again. Just to make sure CYL-6 was on the TDC stroke during the first test. I built and/or rebuilt at least 15-20 engines in my day. Therefore, I'm not a professional. However, I like to think I have a good mind and feel for turning wrenches. Thinking back I have made that mistake at least twice. It does happen to the best of us. I'm sure you got it right. Its the 100% leak down compared to the amount of airflow I could hear that made me 2nd guess your first test. Again I know its an old video. Still, the comments might help someone who is learning. pull out or push in on regulator before twisting. LMAO Great Video Eric!!
"tp for my bunghooollee" 😂
"Are you threatening me?"
Been said many times in the comments, you didn't have enough pressure in the leak down tester. I have the same HF tester. Works like a champ. You have to close off the regulator. Its just there to make sure you are pushing enough pressure (I like close to 100 PSI). Use the regulator at the compressor to limit the pressure to 100 PSI which is the max for the gauge. You will hear where the air is coming from in no time.
Eric, love you videos.
Instead of putting tissue right in the spark plug hole, use the leak down hose and put your finger or put the paper on it.
Mark
@EricTheCarGuy You are right Eric I already got the DTC understood now. My car has 120,000 milles always well maintained. I am referring to the spark plug on that particular cylinder that comes out blackish not dry but slightly oily, the engine doesnt really burn oil not even half of quart every 4 months or so, hesitates a little at low or high rmp. I got new spark plug wires and swaped coil packs and still the same. I´m suspecting the fuel injector is not working well, even though I checked
Is Eric, this car dude, always this cool? And this stoned? I learn so much from ya
I'm kind of surprised no one else commented about this, but when you add air to the cylinder at TDC and you get an unreasonable reading (like 90-100%) the piston probably moved down into the intake stroke, happens a lot if the piston is at, or just beyond TDC it will want to continue rotating filling the cylinder with air as if it rushed past the rings...
Your Harbor Freight leak down tester is just as good as Snap-on and even has the same pull-down lock feature on the pressure valve
Could you imagine the small screwdriver falling on the cylinder...lmao...I did
Chris Choin who cares the motor is junk anyway
Awesome-Subscribed.
Checking out my son's 304 we have some bad compression and now we need to do a leak down test and I have never done that before. Thanks to you I know how now.
Thanks again, Jim
Great video Eric. Very well explained
This was a really good video. I needed to know how to perform this test because my car is beginning to smoke and I'm working on a rebuild. Performing this test first before pulling the engine is what I'll do since the test may result in a little easier job. Thanks again for the informative video.
Did this guy never change his oil?
ha
i want to go change my oil and air filter....
TP for my bunghole😅😅😅 thanks Eric for your instructions you were spot-on. Taking a class on auto mechanics now we're learning about compression testing and leak down test. Your instructions was very well put and I learned a lot thank you sir.😊
I used an old condom I found in my glove box from when I must have been 16 and eager instead of the tissue atop a hose.
10 Minutes to Craps-Roulette Fortune
Hose plus a ballon
@airmalloy Yea that would indicate a leak at the piston, if that's the case then you would need to rebuild or replace the engine to correct the issue. Good luck.
Eric, thanks for a very informative video. Q: if compression (cold engine) is good on all 4 cylinders, but coolant leaks into at least 2 cylinders, is it still possible to be a blown head gasket ? Or is a leaky intake manifold more likely ?
Love your videos! I'm pretty sure the reason your leak down tester didn't work is because you used the compression tester hose extension which has the schrader valve in it, the purpose of which is to allow air out of the cylinder and into the compression tester gauge but not back in to the cylinder (one way check valve), so that it will hold the psi reading on the compression tester gauge so you can read it after cranking the engine over. The schrader valve in the compression tester hose extension will not allow you to hook up air and pressurize the cylinder, the shop air will dead head against the schrader valve. You should have pulled the Schrader valveout of the extension before your leak down test as you did for when you hooked shop are directly to it! Great video anyway! Thank you!
I want to do a leak down test on my STI
nice
I'd see a doctor first, bud.
@@Ass_Burgers_Syndrome lolol
@Jacare1973 Not really as you don't have any traditional vales in an engine like that however it can tell you how much is leaking past the rings if you suspect low compression. In fact a compression test might be a more efficient test for you.
great great information
@ad356 I believe this was a maintenance issue. I did an entire series on this engine replacement including an engine tear down, look under Tahoe engine swap. Thanks of your comment.
I've been replacing my valve stem seals (with the heads on) using the air compressor method. My compressor has the two gauges on it so I'm able to tell the percentage of loss if I set it at 100psi.
All cylinders are good (10% or less) but cylinder 3 loses 30%, and it's coming through the intake. Now I realize the bad valve stem seal has been leaking oil onto an intake valve where it seats and has gunked it up so it's not seating right.
I see your gauge says up to 40% leakage is acceptable, that seems kind of high?? But if that's right, I'd rather not pull the head if I don't have to. If 30% is acceptable, I'll leave it. Is 30% acceptable when the others are 10% or less?
Also, can a leaky intake valve cause the exhaust to smoke? And how bad of a misfire can it cause?
Also, any way to remedy the valve seat with the head on? Perhaps spinning the valve with a drill? I don't need to to be perfect, just better than it is.
+r0llinlacs smoking exhaust is big sign of bad valve seals, usually it smokes at start up then stops or lessens dramatically. if the valve seals are bad you can put the piston at top dead center, pressurize the cylinder with compressed air, (knock the ceramic center out of a spark plug then weld an air hose fitting to it) then remove rocker arm spring ect. from the top being really carful not to knock the valve down. if you do you have to pull the head to get it out.
orput cylinder at bottom dead center, feed piece of clean nylon rope into it until it wont go any more (leaving a tail so you can pull it out) the rotate till tdc and the rope will hold valves up. make sure when you do this its on the compression stroke and not the exhaust or you could bend the valve over.
r0llinlacs
@@chrisgreen4576 i dropped a valve on a dodge neon down into the cylinder. when i bought the right tiny flexible magnet tool i was able to retrieve the valve and pull it back out through the valve guide without removing the head. i also had a boroscope (cheap usb) and some thin utility wire that i looped around the bottom of the valve to angle the valve just right. it was a fun fishing expedition but took about 10-15 minutes once i had the right magnet that would fit down the guide!
@@robbiewilson157 You ought to have been a heart surgeon. Good job!
@urgeone Yea I had the same problem with my HF gauge in this video, that's why I recommended to just use the hose from the compression tester and hook it to shop air to do the test. Good luck.
I found your problem in the first 15 seconds of the video it's a Chevy
you're an idiot
Correct. Chevy/GM products are garbage.
I am studying for A8 reading the book and watching your videos make me understand where i m going for thx a lot