I bought a boosted 03 g35, and when I'm on it under heavy boost it shoots a nasty oil cloud out the exhaust. Under light boost or normal driving I can't see any smoke coming from the exhaust. Engine runs fine, doesn't knock, there is no foam under the oil cap. Just wondering if anyone knows what this could be and/or how to trouble shoot it to figure out what it is.

 

Change your oil. If it has a milky color you have a blown head gasket. Not sure how to diagnose the turbo though.

 

Sounds like a turbo problem to me.

 

If your oil/radiator fluid looks normal it's not a head gasket. Pull your plugs, at least one s/b covered in oil then do a compression test. Sounds like you'll need a rebuild, your G can't be running that well or maybe it never did!
Gary

 

The oil and coolant looks fine, is seemiingly running GREAT. Doesn't over heat, idles fine, doesn't misfire, breaks the tires loose when it hits boost in 3rd and 4th, just spits out a decent cloud of blue smoke when i'm in heavy boost. Otherwise is seemingly normal.

 

The turbo might not have restrictor pills on them. They reduce the amount of oil the turbos see. If you're seeing lots of oil out of the exhaust the turbos may be shot.

 

I had a guy look at it today, and we noticed it doesn't have an oil catch can, and he thinks it's the PCV system. Anyone agree with this potential diagnostic?

 

A catch isn't mandatory it's nice insurance tho. Also I agree a clogged pcv valves can cause the condition you're talking about.

 

Anyone that loves what they drive should have a catch can, inexpensive and keeps oil residue out of your intake. PVC valve "might" cause this kinda issue, clean it with carb cleaner and replace. A few miles should tell you if you've solved the exhaust smoke...Gary

 

An easy way to check is to remove the upper plenum and look for oil.

 

He thinks it's the PCV rather than a bad turbo because he said when a turbo is bad it will burn oil when you're not boosting, and mine only burns under heavy boost. Regardless I will pull off the upper plenum and check for oil and update the thread accordingly.