I think I would look at your comment of "no performance issue" and live with it for now. If you do a lot of short-trip driving, there will be blowby that condenses in the oil and won't burn off right away. If it vaporizes and burns off later, that could make more smoke than normal. There could be an additive in the oil that is vaporizing. Regardless of the cause, if it's not causing a problem and the engine is running normally, I'd leave it alone.
To tell if it is due to worn piston rings, your mechanic can do a "cylinder leakage" test. A compression test will identify any cylinders with low compression. A cylinder leakage test will tell you why it's low. There's four possible causes and four places to look. The causes are a leaking intake valve, a leaking exhaust valve, a leaking cylinder head gasket, and worn piston rings. The leakage test involves blowing compressed air into each cylinder, one at a time, and listening for where it comes out. If the piston rings are worn, you'll hear the air hissing at the oil cap or dipstick tube.
Sorry for ignoring you for so long. My e-mail service went through some changes, ... Again, and I didn't get a lot of automated messages.
Sunday, September 29th, 2013 AT 10:55 PM