What does this compression test tell me?
Joined: Dec 2005
Posts: 6,499
Likes: 31
From: Macon, GA
Car: 1992 Camaro RS
Engine: Vortec headed 355, xe262
Transmission: T56
Axle/Gears: 9-bolt 3.70
Re: What does this compression test tell me?
Do you have the same cylinder heads on both sides of the car? Ever had the engine rebuilt? Really weird that all the ones on the passenger bank are lower than the ones on the driver's bank.
Junior Member
Joined: Sep 2011
Posts: 71
Likes: 0
From: Ontario, Canada
Car: 87 Iroc
Engine: built 355, 450HP
Transmission: built 700r4
Axle/Gears: 3.27
Re: What does this compression test tell me?
looks like you might need a rebuild. there should be 10% difference between the highest and lowest.
Thread Starter
Member
Joined: Sep 2011
Posts: 112
Likes: 0
Car: 1985 Camaro Iroc
Engine: 350 tpi
Transmission: 700r4
Re: What does this compression test tell me?
The engine has been rebuilt. Currently has 170k miles. Also wanna note this test was before the vacumm leaks and idle issues were resolved. I have not checked the cylinder heads. I find this strange as well.
Moderator
Joined: Jul 1999
Posts: 17,262
Likes: 168
From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: What does this compression test tell me?
Do the test again but this time squirt some oil into each cylinder before testing it.
Joined: Sep 2005
Posts: 27,819
Likes: 2,406
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: What does this compression test tell me?
Do it again; but this time, use a hot battery, and blokc the throttle wide open.
Moderator
Joined: Jul 1999
Posts: 17,262
Likes: 168
From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: What does this compression test tell me?
Ooh. I forgot about saying to do it at WOT.
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