Occasional smoke on start up

Lots on this I know, but looking for advise...I get a thick, strong smelling smoke on cold start up but it is only occasionally. Seems if I drive the car a lot, is subsides but not sure of that. Don't drive the car every day for the most part and seems to happen if the car is only driven a couple times a week? I have read all about the air/ oil separator ( AOS ) issues, which sound possible and during my last oil change, my mechanic mentioned that there was a "slight oil leak at the breather tube" which i assume is related to the AOS . Any advise or sure way to diagnose would be helpful. Shop wants a good chunk of labor $$$ to fix the breather tube issue and replace the AOS . I see the part is about 100 bucks....thx for any advise...

Mine smokes every time at start unless it was driven very recently. I chalk it down to oil settling due to the flat engine exacerbated by moderate bore scoring. I replaced my AOS at 100k miles with no change. It's smoked since I got it at 75k with no I'll effects (120k now) except consuming a quart of oil every couple thousand miles.

ssmy, can you say what led u to do your AOS anything specific or just general maintenance...thx

Partially just preventative maintenance since I was doing my 100k service anyways. Also just in case it helped with the smoking. Ended up not helping of course.

An easy test that indicates an AOS problem is to see if there is a vacuum where you add oil. Start the car, unscrew the oil filler cap and place your hand completely over the filler tube, then slowly lift your hand up. If you feel suction, then you probably have an AOS that's beginning to fail.

None of you mention your usage or driving Any DE or AX ? That what usually causes the AOS problems; just like the power steering failures in early cars 98-09 I tracked and autocrossed a lot and had to go to the Motorsport unit which was $1300 installed a friend tech. Never had any smoke after that.

What color is the smoke and what does it smell like? If I park my car after it has been running at operating temperature, no smoke. But if I park my car when the engine is still cold (only starting it to pull it in the garage after a wash), then the next startup is guaranteed to have a single puff of smoke at startup.

What happens is oil that AOS doesn’t control gets pulled up the intake and then burns when you start the car When you have running the car it gets burnt up and not puddled in the intake

Well yes, sort of. There are articles on both the Pelican and LN Engineering sites about checking crankcase vacuum. Per memory, if vacuum is around 5" (water) you are good. Much above that and you likely have a leaking AOS ; much below and you may have bore scoring. So if you have a well-calibrated hand then you could do it. I use a manometer .

This. My 08 does the same thing. I think maybe the cold thick oil lays in the cylinders . First time I saw it I thought I was in deep trouble. Now I always drive it around a bit even if I am just pulling it out for a wash.

My car has always done the same thing as well, it only had 12,000 miles when I bought it, now it has 35,000 almost 9 years old 987.2 I use maybe 1/2 a quart of oil in 5,000 miles with about 8-10 track days.

Based on the responses, think I'll hold off on the visit to the shop. My mechanic said there is always some vacuum when taking the oil cap off as I used that method to check for AOS issues and I don't have a " manometer ". This forum has been so helpful in making these decisions as far as repairs go....thanks to all

It's the oil laying in the intake runners because the AOS can't handle the pressure from doing track days and/or autocross if you are an aggressive driver. It happens a lot and is common to all these car. If you just street the car or only do limited track days you have to just live with it and realize as bad as it looks it's not anything major. If it a newer car get it replace under warranty.

Here a video on testing the AOS from Rennvision

I agree - it's just a normal characteristic of horizontally-opposed motors. Been experiencing the issue with various air-cooled VWs, 911s & 912s since my exposure to them starting back in the late 60s.