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I have a 1988 Chevy Nova/Toyota Corolla I-4 4ALC and just performed a dry & wet compression test. My readings on all 4 cylinders were all about the same.. 1st turn over (puff) ran about 80 psi and 4th turn over ran at about 100 psi.. I then performed a wet compression test and got the same readings. I checked the shop manual and saw that readings should be between 124 - 160 or something very close to that. I'm simply trying to get a few opinions on why the compression could be so low even after performing the wet test. Car has 126k miles, smokes a lot, uses about 1qt of oil every 150 miles, but strangely it runs good!! Could this be piston rings or valves? Any suggestions?? Thanks!!

philiptrammell

It could be any of the pistons, ring, or valves.. or it may be all of them.. if its not leaking water out or into the oil.. then that crosses out alot.. but youre using oil.. so.. just get the heads/head checked and check out the combustion chambers.. pistons.. etc..

Bull dog

Yeah, you are looking at mostly rings and valve ring leaking. Time for an over haul.

Harry

Could be either/both. With that amount of miles, even well-maintained metal components are going to be a little bit worn. While it's slightly more likely the rings/piston walls are a little worn, only a tear-down and inspection would give you a definitive answer.