I am new to the forum. I have a 99 Boxster with 12,000 miles. It has always started with a little puff of white smoke when it sits for a week or so. Today it was a huge amount of white smoke(when cold) and it took a minute to dissappear.
Seems like oil is dripping onto the cylinders. Anyone have any thoughts here? Thanks.

 

Not good, you may need to have your rear main seal checked - do you know about thse issues?

 

White smoke when you first start a water cooled car is a sign that one of the head gaskets is allowing water/coolant to leak into the combustion chamber. When you start the car, it is burning off the coolant. I hope your car is under some sort of warranty. Watch your coolant level over the next few weeks. If it is getting lower, you have a blown head gasket.
Tim

 

the same thing occured with my boxter , i don't think that ther is anything to worry about. sometimes when i let my porsche sit for a couple of days this occures.

smoke porsche boxter 1999

 

On a horizontal engine like the boxster, it is normal for a small amount of oil to drip down into the exhaust when it sits. This will produce a white smoke from the exhaust on cold startup (most will think headgasket, but these engines work a little different than a standard vertical engine). It should occur for only a few seconds, so keep an eye on it, and try driving everyday for the next week or so to make sure the problem becomes less and less.

It has absolutely nothing to do with a rear main seal. There is no way oil leaking from a rear main (on the transmission end of the crankshaft) could cause smoke.