Cylinder Leakdown Testing

[@daveshanton485]

Thanks that was a great lesson. Also, so glad to hear your thoughts on reality… Using the Borescope. For a DIYer, I think you just saved me 35 bucks on a cheap Amazon leak down tester

[@RedondoBeach2]

10:05 Is the only way to know if the engine is set to TDC compression instead of TDC exhaust, to use a screwdriver or straw, as described in the video, then install the gauge and apply air pressure to determine if air is or is not leaking from the exhaust valve(s)? I want to perform this test on my 2004 VW GT, 2.8L VR6 engine. The car runs fine. Intent behind testing is to determine if a more serious engine issue exists before replacing the timing chain. Some oil is leaking from the engine but I have not been able to determine the location. Possibly leaking from the rear main seal for the clutch assembly. Maybe the oil filter mounting point. Hoping it's not a cylinder head, valve cover. Unsure if the secondary air system could also be the culprit. Thanks for teaching us how to do this work. Your knowledge, experience, and meticulous teaching method makes you a great teacher. I especially appreciate the honest fact about how it's done in with a borescope. Personally, I want to try doing it the old school way with the compression tester. A borescope is too pricey for me at this time.

[@MickeyMishra]

One of the BEST leak down videos out there. I saw Eric the Car guys video YEARS ago. But this one is TOP NOTCH.

[@silversilverthorne]

thanks for teaching me like the reality and directions i am old school but like advancement

[@mike-yp1uk]

I like the old school testing. We never know if we will have a bad scope or transducer.

[@77smore]

Thank u for this lesson on CLT. It was such a helpful video. Very detailed.

[@chilleddriving1455]

No way can a borescope tell you if your rings are worn, valves not seating or head-gasket gone.

[@CR-rc5ch]

Facts

[@Mr416cat]

How did you STOP the motor from rotating when you applied Air pressure 100 psi would push the piston to the bottom of the cylinder now you have a valve opening

[@renejacques8288]

When you use the video borescope for valve issues, do you put the cylinder TDC on compression stroke and visibly look for holes where air may escape? Other than the exhaust ports on the head, where else are exhaust ports to listen for leaks? I have a '95 Nissan Maxima.

[@thetomi55]

Great lesson. What in a case where all cylinders on dry compression test are where they should be (no wet compression done) but the CLT shows 65% leak (on all the same). What could be the root cause of that? Engine is VW 2.0 Turbo EA888.3

[@alibatebi2161]

thanks for very informing video i have questions. how worn piston ring can be check with borescope. thanks

[@asmith136]

No where on the internet do they use the tester like you show.. The instructions with the gage also say you are doing it wrong.

[@jackle842000]

Can you do a video on what to look for to tell with the bore scope?

[@chriscrystalhood6260]

Very good demonstration but what was the devil with a pitchfork drawing about?

[@difusekitty3]

best video ! thanks for the great instruction and help

[@jantelow]

What if compression, pcv and valve seals are ok and the engine does not have a turbo, but there is a lot of blue smoke and a lot of oil consumption. The engine has been overheated once. Could it be the oil rings? In my view, a compression test and leak down test will not reveal worn/damaged oil rings.

[@asmith136]

No where on the internet do they use the tester like you test. The instruction also say you are wrong.

[@PeterHernandez-lg2eh]

Tuf to do a wet compression test on a Subaru boxer engine.

[@joecook4451]

im doing this on a atv. does it matter if there is oil and coolant in it? also the compression is 47-81 psi normally. could i still use the 100 psi ? i have tdc front and tdc rear , 1 cylinder each. do i test tdc front then rotate 360 and test again for the front and repeat on the rear?

[@bryanvance6629]

So I have a 2005 dodge ram 1500 4.7 and I did a compression test yesterday. Cylinder 2-8 I was at 150lbs but Cylinder 1 I was at 90lbs. When I tested again this morning by putting a few drops of oil in the spark plug hole it then went to 120lbs in Cylinder 1. I have a knocking sound and it sounds underneath the truck. Thank you

[@MickeyMishra]

that's usually a rod bearing or rod knock.

[@voodoomelons]

Great video, thanks.

[@jimellis1810]

I have a motorcycle that has an auto-compressor on the camshaft which lifts an exhaust valve a bit to make it easier to get the piston a bit beyond TDC for kick starting. Is there any possible way to do a leakdown test?

[@jackle842000]

Wander how you can do a wet compression test on a boxer engine as the oil will all go to one spot on the ring since it's a horizontal head? Seems like it would never coat all the way around the ring

[@MickeyMishra]

Spray oil in the cylinder. Use your shop air to blow the chamber with a rubber hose at the end so you don't damage the threads. This gets oil all over the cylinder bore walls in a flat engine. Spray again for any oil that left IF NEEDED. Like if you blew out all the oil out of the spark plug hole. Use borescope to inspect cylinder for even coverage of oil. IE, its wet. Now quickly perform your leak down test. Repeat procedure for other cylinders. 😊

[@jackle842000]

@@MickeyMishra sounds like a pita but possible

[@MickeyMishra]

@@jackle842000 When you start working on Flat Engines? Chances are? The Labor costs are worth it. There are far more people willing to pay for good work then people who just want slave labor. Yea, it's a pain. But at least its not PT cruiser TIming Belt Install pain. 😁

[@DJ-tn7vj]

Very reliable test. Use it as my last option

[@aviationist]

Yeah, but a CLT is going to show you if your head gasket is leaking as well. So with the CLT you get everything in one shot.

[@luxostucco2772]

If the timing chain has stretched if the cylinder is is at TDC will this put the cam lobes out and valves will be open slightly ?

[@CheapskateGarage]

Not if you're only slightly out of time. Both valves should be closed near the beginning of the compression stroke, and should still be closed near the end of the power stroke. That's nearly 180 degrees of rotation with both valves closed. TDC is in the middle of this range, so it should always be a safe bet.

[@luxostucco2772]

@@CheapskateGarage Thanks for your reply, i think the chain jumped and the can were way off I realigned using cam locking tool them replaced the chain at TDC .

[@jackle842000]

Why would it going backwards a little damage a timing tensioner? Can't seem to make sense of that

[@MickeyMishra]

it has to do with the cams riding on the lobes. going backwards can do some damage on some engines with an overhead cam setup or with another kind of valve train it's just not recommended so to avoid damage that "COULD BE" possible. THere are also valve trains that have things like VTEC or vvt-i or other items that run off the cams that are friend backwards and get damaged and some new your engines. it really is a safety precaution

[@PeterHernandez-lg2eh]

No room for using screwdriver on a Subaru boxer engine especially on a ej257 sti engine😊

[@carlodonnell146]

I don't see how the borescope can tell if the rings are bad. I have a scope too and a leakdown tester and compression tester OTC . And I have been working on my 2001 dodge ram van v8. Num 7 cylinder has the lowest compression but I have random misfires on num 3 and #1 as well, but no codes, nor MIL, I determined that is the rings/cylinders.

[@mrgmrg9943]

thanks you awesome legendary guy

[@FloridaMan7337]

all these videos on the leak down tester use easy 4 cyl to find tdc so what about V engines

[@lizardking8388]

You don't even need to do it the way he described. There is a much easier way to find TDC on compression stroke of any engine. 1) Hook up your tester to the cylinder you want to test and put around 10 psi into the cylinder. 2) Turn the engine slowly while observing the needle on the gauge. 3) At some point the needle will start bouncing in the positive direction (you're now on the compression stroke). 4) Keep turning and observing the needle. 5) Once the needle goes to the negative, you've just passed TDC. 6) Back up the amount you last turned and you are at TDC. 7) Slowly raise the pressure to 100 psi and note your leakage. The needle on the gauge acts like the screwdriver in the cylinder. It goes positive on the way up and negative on the way down. If you follow the firing order of each cylinder to be tested, you will have the least amount of turning to do as each cylinder at TDC in the firing order is 180 degrees apart.

[@PeterHernandez-lg2eh]

E even tougher is a Subaru ej257 boxer engine

[@TropicBreezeRealty]

How long should a cylinder hold compression?

[@MickeyMishra]

depends on how worn the engine is and whether it's hot or cold. There's a lot of factors. if it holds it for at least 30 seconds to a minute you're golden for a daily driven car imo. but this varies from engine to engine

[@TropicBreezeRealty]

@@MickeyMishra what about a rebuilt 351 that hasn't run. the rings haven't seated and isn't holding compression.

[@MickeyMishra]

@@TropicBreezeRealty Then something FUBAR on the REBUILD. Best I can say without being there. I have this saying. If YOU did not rebuild it? Did not pay a Kidney to get it done? It may have issues with the rebuilder. When I drop anything at the machine shop? I buy them Lunch. Drop of cases of beer or Soda for the shop fridge. Most of the time? This works a treat when I have others rebuild things for me. Your mileage may vary. I would take it out and inspect everything and check tolerances. Things happen. Even with new parts.

[@Brion-qn3vi]

Subbed ~

[@renderuthis]

he has a chart1 Ill click on that.

[@user-lp3cf5yn5b]

Si

[@jerryeastman8393]

NEWS FLASH... If you have a hole in a piston that cylinder isn't going to pass any sort of a leak down test. certainly a wet test for ring failure. listen to yourself. LOL.

[@scottcard672]

But you would hear the air coming out of the crankcase.