1niceSi

i know this is the wrong forum, but i wanted to get as many views as i can.

does anybody have the tools/equipment needed to do a compression test?

on wed, i'm going to check out a motor that i might potentially buy, and i want to do a compression test on the engine. the engine is still in the car, but i want to do one anyway.

hopefully, quick cx, bb1_eg6, and Jooksingkid can come along with me to guide me in my decision making process.

if nobody has the tools/equipment where can i get them from?

or is a compression still necessary since the engine is in the car.

i won't be back to check this until monday...so thanks for the help in advance.

Quick_CX

yo james my shop has one i can ask him if i can borrow it..i dunno if he'll let me...but generally if the engine is running fine ...it will have good compression

imported_loudsubz

compression tester from wal mart is like $17 or so, pretty simple, then pull fuel pump fuse, crank err and read gauge.

bbarbulo

iTrader: (2)

I have the WalMart compression gauge, you don't have to pull the fuel pump fuse, just unplug all the plug wires, pull one plug at a time, screw the comp gauge in there and crank 2-3 seconds then get out and check the gauge. Release the pressure using the little side valve, and unscrew. Put the plug back in and move to the next cyl. My saturn with 206K miles (about 330K kms) tested at 155 on two cyls and 170 on the other two cyls. That's well within spec, but does indicate either tired valve seals or a bad head gasket. About 200 psi is excellent, and about 120 psi is the minimum needed to run. I did a dry test rather then a wet test. Wet test indicates the condition of your valve seals, cuz you pour a little oil in your cyl to seal the rings up, so if you get the same reading as the dry test, you know your valves are the culprit, not the rings. If the rings are bad, your compression numbers on the wet test should jump up a bit.