Compression Test.......

[oonighttrain]

this may sound like a stupid question but, my buddy is finding it hard to believe..

when doing a compression test, if you put some oil in the cylinders and the compression reads higher, proves you have a problem in the cylinder (rings etc..) not the head.. true???

 

[JB]

Re: Compression Test.......

Not necessarily, oo. There will be an increase even if the rings are in perfect shape, just not as much as with a lot of blowby.

A leakdown test is a much more reliable method of checking the rings.

 

[oonighttrain]

Re: Compression Test.......

Not necessarily, oo. There will be an increase even if the rings are in perfect shape, just not as much as with a lot of blowby.

A leakdown test is a much more reliable method of checking the rings.

well.. i should have worded it differently.. my #1 cylinder went from about 15 psi. to over 100 psi. would you guess rings and/or worn cylinder?? gotta be the cylinder is screwed, cuz we just put rings in it...

 

[JB]

Re: Compression Test.......

15psi to 100psi? Yeah, I would think I was in trouble as soon as I got the 15psi. No need to add oil.

 

[JustJason]

Re: Compression Test.......

i bet you loaded up your compression gauge with oil

seen that happen a hundred times.... even blew up one of mine that way years ago.

now i don't even bother with oil in the cyls..... if i got low compression I spin that cylinder up to tdc, throw a piston stop in another cylinder, and break out the leakdown tester.