4G63 compression?

[96spyderman]

About 2-3 weeks ago I was doin some drivin-HWY, easy goin. Wife and I went looking for new vehicle for her... got to a dealership and got out to look at something... I noticed some bluish smoke (smelled like oil)coming from the muffler.
I did a compression check on all 4 and they all were at about 105 psi.
My thoughts of the rings goin bad/burning oil were set aside.....

My question is what are they supposed to be/PSI? and what else would cause an oil burning problem? Valves?

[scottsee]

http://www.geocities.com/dsmgrrrl/FAQs/compression.htm

[metalhedskater]

where can you get a compression gauge at btw?

[96spyderman]

Originally Posted by metalhedskater

where can you get a compression gauge at btw?

Checker, Napa, wherever


OK here is info for me....

2G (95-99) 2.0L 4G63 Turbo engine
Compression ratio 8.5:1
Standard compression 178 psi
Service limit 133 psi
Is the service limit what I think it is... if it's less than 133psi it needs to be fixed?

I'll have to do the check again... hopefully I end up with more than 105 psi again!!!!! Maybe thats my power loss I feel when boosting at 12-13.

[1stGenRocks]

it could be your rings. does your dipstick pop out when you boost? when you do your compression test do a dry then a wet test. first check it normally (dry test) then pour a tablespoon of oil in each spark plug hole wait a few minutes and test the compression again (wet test). if the compression goes up that means your rings are going bad.
if you have the machine for it you can also do a leakdown test which involves filling the cylinder with compressed air and it gives you percentages for where it leaks out from. 10% from the rings, 10% from the intake valves, 10% from the exhaust valves, etc...


edit>>> yes you are right about the service limit. the compression shouldnt be lower then that

[metalhedskater]

Originally Posted by 96spyderman

Checker, Napa, wherever

Thanks a lot man! Didnt mean to interfere with your thread .

[96spyderman]

OK... did another test today.... If you are looking at the engine from left to right my readings were as follows....
175psi...170...165...150.

I found it odd that they went down like that.... I suppose that could cause some of the powerloss feel...... Heck of alot better than 105psi I had the first time!!!! lmao
Thanks guys!! Any suggestions or thoughts please spill it.

[joemathews]

Just to make sure....

1) You did the tests on a warm engine (at or near running temp)
2) You allowed for 4 full rotations while cranking
3) You held the gas pedal at WOT while cranking

If you did all of that, you should have a decent compression reading.

I also have the burning oil problem--not a huge cloud of blue smoke following my car, just a little puff now and then when taking off from a stop, or revving the engine in neutral. Possible ways to burn oil are:
1) bent valves/bad valve stem seals
2) bad piston rings
3) bad turbo seals
4) bad PCV valve

I am investigating these on my car as well. My compression numbers are 180-170-175-180. I can't imagine having compression numbers that high with bad rings or bad valve stem seals, but I am no expert in the area. I'd be interested to get Kevin's opinion though.

Next on my list is replacing the PCV valve ($5, easy to get to). The turbo will also be replaced soon enough . I just can't wait to finish the 4 finals and 3 papers I have due in the next 12 days so I can get this stuff sorted out.