hey everyone, i have a question about compression readings on my cousin's car. It is a cammed 2002 camaro. Motor is stock besides cam. The shop he has it at did a compression test and only got 80psi on all cylinders. It is a low mileage motor, less than 30k on it. They have been working on it for over a month now, and it was at a different shop before this one for three months. The car is not running right, and i told my cousin that 80 psi sounds way too low for compression test. We think that the cam is off a tooth, but the shop says no way. They keep looking for electrical issues and i think they are looking at the wrong area. Does the compression results sound low to you guys ? Any motor i have ever checked, the psi is usually like 150 to 175, but i am not too familoar with the ls motors. BTW, the car ran fine, actually ran 11.9 last fall, then the cam was installed over the winter and it has been messed up since. Seems like the cam is off to me.

 

80 psi is very low. It's not very hard to pull the water pump and front cover and check cam timing isn't off by a tooth. Ls1s are 10:1, I would think with those low miles that you should see 160-190 depending on cam specs. Regardless, 80 is extremely low and not acceptable.

 

thanks, that is what i thought too.

 

Start looking where the changes have been made since it last ran well.

Who did the cam install?

(I'm assuming the shop is saying the poor running is an electrical issue, not that the low compression is an electrical issue.)

 

my cousin installed the cam, and then took it to the shop for a dyno tune. When he got the car back it ran all messed up at low rpm, but ok at high rpm. He then took it back to the shop and they had it for almost 3 months. They deleted all types of sensors and tried new pcm and different tunes, and did not fix it. He finally told them to check the cam and they never did. So he got tired of calling and bothering them, and never hearing back from them. He took the car to a different shop, and they straightened out the PCM tune from the last shop, but now they can't figure it out either. We told them to check the cam, but they said no way is that the problem. I am a mechanic myself and i think they just do not like someone else helping to figure the problem. I told my cousin that he is their boss, tell them you want the cam looked at or go get your car back. We are most certain that is the problem after the compression results.

 

yes, the poor running is an electrical issue is what two different shops have said now, but they keep trying all types of things that are not fixing it