911 Smokes after not driven for a week
 

I have a 79 911 Targa with 190000. original miles. The car runs beautifully, however, if I don't drive it for a week or so, when I first start it up, there is about 30 - 45 seconds of white smoke from the exhaust. If I drive it daily, not a problem. Any thoughts?

Maybe oil seeping past valve guides....have you ever had a top end rebuild?

Jaicar-
There are MANY threads on this subject. The most common source is that oil has leaked past the rings after sitting for a while. This is inherent to the engine design where oil fills up the case after the engine is shut down. Due to the horizontal arrangement of the P&Cs the oil reaches the backs of the pistons and wallah... After sitting the oil can leak past the rings.
Another source is condensation built up in the exhaust.
Try searching the forums for more info. Here's one such thread:
http://forums.pelicanparts.com/porsche-911-technical-forum/504304-how-diagnose-smoke-start-up.html

Cheers

Thank you! My mechanic kind of said same, I just wanted confirmation.