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low compression on all 4 cylinders

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matt98eclipse

15+ Year Contributor
1,078
0
Aug 15, 2006
mesa, Arizona
Hey guys i just purchased a 95 gsx. Previous owner said that he had bought a brand new motor and car doesnt have that many miles on it. Well when i bought the car it he told me the motor was smoking a bit due to a bad turbo he said. Well i put on a known good 14b turbo and fired car up and noticed the car is still smokeing a bit.... Car seems to smoke more as it get warmer. The smoke color looks to be blue like its burning oil someone.. So i did a compression test and on all 4 cylinders and it came up with between 135 to 140 on ALL 4 cylinders.:banghead:


What do you guys think my next step would be to do to pinpoint my problem?
 
I did the test with motor at operating temp and WOT and makin sure its not getting any spark or feel.

I havent done a leak down test yet cause i dont have one.

I did a dry test first then on cylinder 1 i went ahead and added a cap full of 10w40 oil and compression only went up to around 150..

Car is smokeing pretty bad.. one thing i did noticed is i looked at the top of all 4 cylinders threw spark plug holse and noticed they looked a little wet but didnt smell or look like oil at all. Also i know the car used to run really rich cause previous owner forgot to plug in front o2 sensor and lots of boost leaks!!
 
You can rent a tester from Autozone, or probably other parts stores.

It's probably either rings or valve seals, but your story leads more towards pistons rings.
 
Do a leakdown test to see where the pressure is going. With the story of the car running rich, i'm inclined to think rings. Washing down the cylinder walls on a new engine can lead to your type of problem. Or, the engine isn't new, and has bad valve stem seals. Or, the engine isn't new and has bad rings, could be a lot of things.
 
Good advice up there. Running rich will wash out the cylinders even on a perfect engine build.

Another thing to check when compression is low on all cylinders (although I doubt it in this case), is that the timing marks all line up. Too much E/I overlap will cause low readings all the way around.
 
Good advice up there. Running rich will wash out the cylinders even on a perfect engine build.

Another thing to check when compression is low on all cylinders (although I doubt it in this case), is that the timing marks all line up. Too much E/I overlap will cause low readings all the way around.

very good point ill have to check this as well but this wouldnt cause it to be smoking a bit would it??


The motor has a pretty bad lifter tick is sounds like.
 
I've been searching as much as I can before I create my "Low Compression After Head Install" thread in order to cover all the bases or possibly fix before I post.

Have you solved this problem?
 
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