Compression Test?
Thread Starter
Heel & Toe
Joined: Apr 2006
Posts: 15
Likes: 0
Compression Test?
Hey guys, My brothers got a 2001 c5 vette and we did a compression test just to see what it was doing and we got a compression test of 90. We did the test on two different cylinders to make sure it wasen't a bad cylinder. Just wondering why its so low? Car is stock except borla exhaust, and runs great.. Thanks Kev.
Thread Starter
Heel & Toe
Joined: Apr 2006
Posts: 15
Likes: 0
Originally Posted by usd2sing
should do all cylinders.
was the car/motor warmed up?
everybody usually says a leak down is a much better way to test for a dead hole.
was the car/motor warmed up?
everybody usually says a leak down is a much better way to test for a dead hole.
Burning Brakes
Joined: Jan 2005
Posts: 1,066
Likes: 2
From: fort worth texas
sorry for getting to this sooner...instant email thingy wasnt working..
FYI:
leak down is where they pressurize the hole/cylinder with air. measure the amount of loss during a specific time frame. good test for ring seal or cracked piston.
they can also do a wet test if a hole is off. by adding a little oil into the hole thru the spark plug hole. good way to test valve seals.
EDIT: maybe some of the more knowledgable gurus will chime in. but i believe thats the basics.
FYI:
leak down is where they pressurize the hole/cylinder with air. measure the amount of loss during a specific time frame. good test for ring seal or cracked piston.
they can also do a wet test if a hole is off. by adding a little oil into the hole thru the spark plug hole. good way to test valve seals.
EDIT: maybe some of the more knowledgable gurus will chime in. but i believe thats the basics.
Racer
Joined: Aug 2005
Posts: 251
Likes: 32
From: S/W Illinois
Accurate compression testing requires a specific procedure. Loosen plugs one turn then fire up the engine to blow out the loosened up carbon and keep it from holding the valves slightly opened. The throttle should be open during cranking so the engine can get air to compress. I've never figured out how you can warm an aluminum engine, then remove the plugs. Plug removal should only be done with a stone cold engine.
