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Forum namePerformance/Engine
Topic subjectCompression check results.... please help
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=56784
56784, Compression check results.... please help
Posted by Eagle 5, Aug-06-03 04:19 PM
Did a compression check on my car few minutes ago and here is what i came up with. did this since i bought a turbo for it and also i have a oil consumption problem.

Cylinder 1 = 210 spark plug was fine
Cylinder 2 = 180 spark plug was fine
Cylinder 3 = 210 spark plug had oil on it
Cylinder 4 = 210 spark plug was fine

Added a cap full of oil to cylinder 2 and let sit for a minute then redid compression check on it...twice

Cylinder 2 2nd time 300 !!!!
Cylinder 2 3rd time 270 !!!!


My conclusions and the guy who helped are that cylinder 3 has bad valve seals and that is why oil is on it. Also i replaced the PCV valve and found oil in the tube and the valve

Cylinder 2 piston rings must be going out if the compression jumped that much, or something else happened or is happening.

SO what does anyone have to add or what not?
56792, RE: Compression check results.... please help
Posted by soldier101, Aug-06-03 04:51 PM
hmmmm headgasket issues?
56796, RE: Compression check results.... please help
Posted by Eagle 5, Aug-06-03 05:47 PM
doubt its the headgasket. my coolant level is where it always is. no leaking and no smoke coming out exhaust.
56799, RE: Compression check results.... please help
Posted by 95ALLmotorFWD, Aug-06-03 06:29 PM
DUDE! those numbers are perfect just about, in that cylinder with 180, dont worry about that, thats normal wear, its very common to get one 20 or less lower than the other cylinders, so dont worry about that, second if oil was on the plug, thats the spark plug gaskets on the valve cover not your valve seals, i just re did mine with a new valve cover gasket as well, you lookin good dude, just keep changin her oil and do reg, maintanance and your all good!:thumbsup
56811, RE: Compression check results.... please help
Posted by coppereclipse95, Aug-07-03 04:02 AM
^^^^says. I think you need to start worrying, when the lowest number is 75% of the highest number. So, I think you are ok also. but, if it gets lower...then maybe you need to start thinking about it. but, you should be fine!!
56814, RE: Compression check results.... please help
Posted by Eagle 5, Aug-07-03 04:47 AM
i ordered a turbo kit. so that will be going on when i get it in a few weeks. but im just wondering if maybe the rings are starting to go in that cylinder? seems like it could be rings or it may be something else. just that all my cylinders were 210 except that one. im goign to a mechanic i know today and see what he thinks, maybe get a leak down test done just to see if or why comrpession is lower in that cylinder and maybe why oil is on the plug in number 3
56874, RE: Compression check results.... please help
Posted by thedawg, Aug-08-03 09:19 PM
Don't even worry about it. The rings will hold up just fine, no matter how worn they are. Your pistons will eventually crack after being turboed for a while, and you'll take care of everything when you rebuild.
56882, RE: Compression check results.... please help
Posted by Eagle 5, Aug-09-03 10:47 AM
well im not too worried about it anymore. im rebuilding anyway so it does not matter.
56900, RE: Compression check results.... please help
Posted by Matt_95tgs, Aug-09-03 05:36 PM
Yea, cylinder 2 may be a bit worn, but it wont be an issue. You will break the piston ring lands way before you have problems with the rings themselves. Boost away.