I did a compression test, and the numbers suck!!!!!

[kickertu]

well i finally did a compression test, on my sr, and i think the motor is fuked..
the numbers are as follows.

1- 115
2- 90
3- 90
4- 85

does this mean my headgasket is shot? or are my rings shot?

[uiuc240]

First of all, the range is a bad thing. But before getting to that...did you do it right? The motor should be warm at the time, and when you do the test, the throttle should be wide open (disconnect fuel pump fuse so you get no fuel).

This could indicate head gasket problems, ring problems, and also valve problems (might not be sealing).

If you do the test again and you still get back numbers, it's time to take the head off.

Eric

[AceInHole]

should also have all sparkplugs removed. otherwise the engine will have to fight itself on the compression stroke.

[kalieaire]

also when you do the compression test. do it once with the methods listed above.

IF you still get low compression, drop in a cap full of oil in the cylinder prior to testing. if the pressure stays low, then you need a valve adjustment or your HG is fried.

IF your compression goes UP, then it's your rings that are fried, that or you have scoring on the cylinder walls.

If you suspect scoring on your cylinder or pistons, get a leak down test, it'll tell you w/o a doubt which it is, and where it is.

[kandyflip445]

On a side note you can also use ATF for a wet-test. This will help clean out carbon build-up. But, that might be helping you to get any compression...:p