Compression Test on a Evo 8: How to
ฝัง
- เผยแพร่เมื่อ 24 ม.ค. 2019
- Before installing the FP red I wanted to do a compression test to see just how healthy the engine was.
130
130
130
135
Test was done with the engine at operating temp, but the throttle was closed. I forgot to hold the Tb open. Numbers might have been a tad higher if the gas peddle was pressed down. - ยานยนต์และพาหนะ
![How To Perform a Compression Test - [EASY]](http://i.ytimg.com/vi/3VmmL0YAO14/mqdefault.jpg)
![How To Perform a Compression Test - [EASY]](/img/tr.png)
Noise at 4:44 I've always wondered about myself. Any idea if you key was still in the on position? Wonder if it's the ISCV/IAC valve adjusting..
I dont remember if I left my key on or not. I was going back and forth so much I didnt take any mental notes of the key position.
Its actually the first time I have ever heard it
Ok, I need to do this soon as well. What about the wet test (drop of oil on cylinders) as well? Isn't this meant to give a more thorough test?
A drop of oil isn't needed. Warm up engine. Pull all plugs. Perform test.
If you think you have low numbers in a cylinder, the oil through the spark plug hole will tell you if your rings are bad. The oil will seal the ring a bit bumping the numbers if you did a retest.
Hope that makes sense
@@d-evolution1309 Ok thanks, I think I get what you mean. Only do the wet test if one cylinder shows up with weak pressure to determine ring problem. I basically have some blue smoke from exhaust when I rev engine once warmed up, so hopefully if test rules out rings then maybe valve seals.
hello there. i notice that your 2nd cylinder from the passenger side is white compared to the others. Is there a reason why?
No idea
I have a evo 8 with a stroker kit. My compression test was 150 120 120 150. Do you think these values are normal? There was about 20% difference in the cylinder between the first and last one with the two in the middle. Let me know.
Id say thats not normal. The 120 cylinders are low comparatively. You might have a headgasket problem between those two cylinders
You should prob have a leakdown teat performed.
You losing coolant or smoking out the exhaust?
@@d-evolution1309 i don't lose coolant. In the two cylinders that have a pressure of 150 PSI it loses some oil from the valves.
@@raffaeleorefice4730 So the cylinders with 120 compression do a restest
This time put a bit of oil down into the cylinder before testing. If it goes. Up from 120 then your rings are the problem.
If compression doesnt go up then it's probably the valves not sealing
my compression test came out to 178 - 160 - 178 - 178, should i be worried?
No. I'd say your motor is strong
@@d-evolution1309 why is my cylinder 2 18 psi lower, new motor was installed 22k miles ago
@@GSekong retest and put a drop of oil in the spark plug hole and see if the number goes up
What size is the fitting that you used?
Don't remember. It threaded into the plug threads easily.
@@d-evolution1309 Need to buy a compression tester asap and can't find that info anywhere. Don't want to buy a kit only to find out it doesn't have the exact fitting I need. Thanks for responding anyhow
@@1CraigE1 it should have them. You can rent a compression tester from autozone or discount auto or oriellys if you have them close by
seems kinda low. should be around 160ish
Perhaps. I did forget to hold the tb open at wot so that might give it a lower psi rating. Maybe.
I was expecting about 150ish.
I got around 130-135 across all cylinders aswell but the car runs fine? Any suggestions
@@Jackvue5 you can do a leak down test. It will determine if its at 130 because of the rings or the valves. If You have a smidge of leakage at the valves you can refresh that to get some compression back.
If it's leaking by at the rings not much you can do except a full tear down
@@d-evolution1309 Thanks, when i bought the car all pistons were at 150. I bought a cheap compression tool to test and thats how they're at 130. I hope its just that dodgy tester!
@@Jackvue5 make sure engine is up to operating temp. Run for about 15 min to get oil hot too.
Be sure to disconnect fuel injectors or pull fuse for injectors.
Hold throttle body wide open.
Cold engine and closed tb can cause lower numbers. Not sure if you knew this or not.
i think your gauge its no good,,,cant be too lower,,,should be 160 to 170psi
You could be correct. I didnt try a diff gauge to verify.
I also forgot to open the tb when I tested too which is prob worth a free psi of compression