Fatguytinyhonda

What is the acceptable range on compression test ? What sorta readings would bad rings give off vs bad headgasket? Or is that a silly question. I just bought this potential money pit of a dream car with small bolt on mods done already and lots of well worn parts. The guy I bought it from was a idiot. So I'm worried what I might've gotten into. He said he replaced the starter and radiator. It needed a clutch cane with new clutch in trunk. Drove home and has drivin for almost 2 weeks now with some clutch slipping only when you get on it. But that's not even the issue. It has headers and catback exhaust installed and I noticed it would burn a little oil and then started over heating at first wasnt too bad. I assumed it was due to the headers having no heat shield or wrapping but then a hose going into the back of the head due to oil leaking onto it over time softened up and started leaking. I fixed that added coolant started over heating again so I made sure the fans came on they do but ones kinda burnt from the heat the others seen better days and has part of the shroud missing. I've wrapped the headers since all that as well but I'm still getting a over heating issue and having to add a little coolant each time. The oil level has been fine and no milky mess or water and no oil in the coolant . No smoke when it's running. So I'm just trying to eliminate all the possibilities. Next step was replacing both fans and double checking compression on the cylinders. Any other ideas where to go with this?

Aradin

For compression you're mostly looking for consistency across the cylinders and not a hard number value. The factory service manual does have "ideal" and "service limit" values but in my experience each compression tester will read a bit differently. As long as there is no more than 20psi difference between any two cylinders it should be fine in that regard. Around that or more and it's likely you have some sort of issue in the lower cylinder(s) and should do a leak down test to investigate further.

Fatguytinyhonda

I've never heard of a leak down check or test please explain I've seen that same thing in other threads on here..

Aradin

You can find more in depth information if you search. It's basically just a test to try and found out where the cylinder is leaking. It can give you an idea if it's losing compression at the rings, valves or headgasket.

Fatguytinyhonda

I've never heard of a leak down check or test please explain I've seen that same thing in other threads on here..

ross2004

Google: "Leak down tester"