so i just bought a 350z and it smokes tons. there is oil in the exhaust.
car has 103k on it, drives nice but smokes

i just did a compression test and results were...

drivers side (front of car to back)
105-120-105
pass side(...)
180-100-120

i think compression is supposed to be around 185 from what i have read.
im thinking some of the rings are stuck with carbon (well most except for the 180 one)

anyone have any ideas on how to repair this? i read you can leave some magic mystery oil in the cylinders for 2 days and it will eat the carbon up. might try that before i take engine apart to change rings...

thanks

 

oh and i was not able to warm engine up before the compression test(know that will affect results somewhat)
some are saying to leave atf fluid in cylinders to eat carbon, some say marvel mystery oil. at this point it wont hurt to try something before i tear it down.

 

Magic oil or snake oil won't help you. You probably have a head gasket that needs replacing. That's kind of spendy and labor intensive.

 

no its carbon rings. 99% sure. thanks for your input though...

 

Hmm, did you try scanning for codes? Might as well try to eliminate the easy stuff first.

 

no engine light or codes. drives great but smokes alot lol. does not overheat or anything. coolant nice and no mixing.

going to park the car in my shop and try both atf and mystery oil and if that doesnt do it then i will pull engine apart and change rings(connecting rod bearings while im in there and clean out any sludge or carbon.)

wont be until end of month as i have other cars to work on right now. just figured i would see if anyone had this issue before.

 

rings or head gasket doesnt matter ... time to pull the engine and tear it down or swap in a donor block...

why cant you warm the engine up?
Is the smoke blue/black? or white?

 

well no its not time yet lol. going to try to unstick them first. have done this before on other cars with success so will see...
if not then i will take apart and change parts. but no harm in trying to unstick them.

 

Be sure to take pics of the offending parts so the rest of us can see what's causing it. May help a future member, too.

 

I hear what you're saying ... but why would carbon build-up be inconsistent enough to cause the compression results you've gotten?

and once the aforementioned carbon build-up is cleaned up, this will allow the rings to seal to the point where your compression is consistent?

 

if you are 99% sure.....why did you post?

 

What color is the smoke??

 

 

Compression should be 130 to 180.

Check your oil, I see people saying head gasket. If that's true your oil should look like light coffee instead of golden clear or black. That means water is in your oil aka blown head gasket.

 

 

You could of diagnosed the rings with a wet test. . .

 

Leak down test might be better, but from what you're saying I'm guessing the rings have just seen better days. Hopefully, I'm wrong and you can clear out the garbage and get some compression back. If you do find the compression comes back, the valves seals would be my second guess.