Thread: compression test

Ok i performed a compression test on my USDM sr20 with the car up to operating temp and got 150, 150, 115, 125 just too make sure this is a bad head gasket??? right???

could be any of a variety of reasons. Compression check just tells you what cylinders are strong and which aren't. To find out probable causes you need to do a leak down test.

yes good idea!!!

Actually better than a leak down test would to do a wet compression check first. That will tell you if its the rings or the valves and requires a LOT less work

you need to do more checks than that to determine if its a headgasket, could be a number of things, such as headgasket,valves,pistons,rings,ect

Yeah, but after a wet check you do a leak down anyway to make sure you accurately pinpoint the issue and don't have multiple issues, so I usually just skip that one anyway. But if you're not at a place with compressed air then it's pretty much all you've got left.

yo held the throttle open when you were doing the compression check right?