Smoking Eshaust on tickover.

Question if i let my car idle, after 6 minutes exact its starts to smoke. On start up nothing at all and general running nothing at all. My car does not seem to use oil or make oil and coolant level stay constant.
The fumes are a mixture of oil and fuel mixture.
Any ideas? Was contemplating a compression test, then a check of the valve stem guides but i would of expected these faults to show on start up.

Had an Alfa that used to do that and the bad news is it was piston rings. If its putting out oil smoke it must be burning some oil......a very small amount of oil looks very smoky. After a year of running the Alfa every day it had started smoking at such an alarming rate that I stopped putting any new oil in it (queueing in traffic got embarrasing and smelly!)and hey presto when the oil level got below minimum it really slowed down! I ran the engine for another 6 months with almost no oil and it never missed a beat