Weird compression issues (Again). What would cause this?
04-03-2009, 09:13 PM
#1
Weird compression issues (Again). What would cause this? Long story short I ran a compression test a little while back and the numbers bothered me. I posted up about it a little while back as well. Well the numbers were done on a cold motor which gives all kinds of awkward readings but I did it none the less. The results were compression numbers ranging anywhere from 185psi down to 155psi... ouch. Well I was told to do them warm and see what the difference was so I did, and this is where it get's confusing...
The warm results were much more even but what's funny is the numbers all evened up at 175psi... Now how can a number go from 185 down to 175? I understand jumping from 155 up but shouldn't the 185 have risen as well?
Also.. those are the actual compression values. I thought my gauge was reading low but it's not. It's accurate which is kind of disturbing as well. Those numbers seen very low.
Little background on the motor... it's a 2002 with 17k miles on it. Bone stock car...
The warm results were much more even but what's funny is the numbers all evened up at 175psi... Now how can a number go from 185 down to 175? I understand jumping from 155 up but shouldn't the 185 have risen as well?
Also.. those are the actual compression values. I thought my gauge was reading low but it's not. It's accurate which is kind of disturbing as well. Those numbers seen very low.
Little background on the motor... it's a 2002 with 17k miles on it. Bone stock car...
04-05-2009, 08:44 PM
#4
My engine sat for 2 years, 7 cylinders were 0-60 psi and one was 135 psi without it having been run. worried me a little. Everyone told me to take it out and rebuild it. I started it and ran it. I now have 155-158psi or so on cylinders. I remember there only being a 3 psi variance. I would wait until its been warmed up until you try to do a compression test.