Blue smoke on start up
 

I recently purchased a CPO 2010 base Boxster with 5500 miles. About one out of every ten times i start the car a fairly sizable cloud of blue smoke is produced. My Porsche dealer says this is not unusual. Anyone disagree?

Depends on "fairly sizeable". Any excessive use of oil? If so, ask the dealer to borescope the engine for cylinder scoring.

Thanks for your reply. I have not checked the oil level in the past several weeks but the last time i checked (at around 3000 miles post last oil change) it showed I was registering three quarters full.

Mine has smoked twice in 1 1/2 years after I was parked on a hill. Not on level ground. ?????

That was not the case with me. I was told that: with these horizontally opposed engines, it is not uncommon for a small amount of oil to be left in a space where it doesn't drain completely and therefore burns off on start up. The amount of blue smoke is fairly large in that it fills my rear view mirror. What is curious is that if this were common, why does it not happen more consistently?

It can be inherent to the engine design. That being said my 02 986 S (52000 miles) almost never smokes when parked on level ground and when it does, it is never "sizable"... Are you sure what you are seeing is not a tiny bit of smoke combined with a sizable amount of steam?

My 2004 S does that occasionally too. The pattern I've detected is it smokes on the next start after the car was driven without getting warmed up such as moving it out of the garage temporarily.

air oil separator needs to be replaced.

Could be the AOS. To check it, remove the oil cap with the engine running, then put your hand over the opening to seal it off. You should feel just the slightest vacuum if its good.

Could be normal or could be AOS.

It is somewhat common to get a big billow of smoke on startup that will fill your rearview mirror. In fact, the first time it happens you will think that your engine just blew up! As long as it only happens occasionally, there isn't anything to worry about.

It could also be the start of a failing AOS. If so, don't worry, it will get worse and you'll be laying down smoke screens worthy of James Bond very soon. That will be the clue that tells you to have the AOS replaced.

Only first hand experience will allow you to determine whether this is just the normal flat-six random smoke or something more serious. My guess is that your engine is fine.

These flat sixes can put out a bit of smoke depending on a lot of variables including gradient and how they were driven last time. I find if I start my car briefly from cold then shut it off (if I'm just moving it out of the way of something on a drive for instance) and come back the next day and crank it, it will smoke. It's also much more likely to smoke if not parked on a completely flat surface.

Great feedback....thanks everyone. One more note: when I brought the car in for its state inspection (which includes an emissions check), it passed without issue. From what I have read regarding the Air Oil Separator, if this were a chronic problem, I would assume it would have failed the emissions test.

I do look for similar variables when it happens (was the car re-started after a short period since being shut off; was the car on a non-level surface; had it been sometime since the car was started) and none of them seem to be consistent.

I will continue to monitor and ask that my Porsche dealer check the vacuum and AOS at my next oil change.