Low Compression

[ElChupacabra]

I got my 4g63 compression tested, and piston 2 is at about 100ish compression, the rest are around 180

probably explains why I had mods for over 300 hp and dynoed at 240

Is there anything I can do short of a motor rebuild to fix this ?

 

[eclipse90gsxt]

Did you do a wet test with a little cap of oil?

Do a wet test, where adding a cap full of oil, then test the compression, if it goes up its your piston ring, if it staysnaer 100 its the valve/valves.

Of get a shop to leak test it for you, and find the problem.

 

[SilverJester]

yep he's right...If you go to vfaq there's info on how to do the wet test (and if you have the very expensive gauge, there is even info on how to do the leak down test).