Smoking with new AOS after DE Event. Help.

[unhcampus]

2003 Boxster S, Oil Castrol Edge 10w 40

After my 20 minute DE sessions I perform a very easy cool down lap. When I restart the car an hour later a good amount of orderless smoke comes out for 3 seconds.

I replaced the AOS with a new unit and have the exact same problem. The car runs fine around town and on the highway and only blows smoke after a track session.

The car is on street tires, the track is NHMS (vicious left hand banked corner), and I run in the blue group. Other Boxsters and Caymans at the track do not smoke at all.

Help.

Also sometimes coming out of the sharp banked left hand, the check engine light flashes. A OBD reader shows misfire in cylinder 5. This happened at the exact same point on the track 3 times in a row.

[Topless]

Check your oil level. Oil overfill will cause this every time.

[san rensho]

After you get back to the pit, idle the car for a few minutes. Oil tends to pool in the heads after a hard run causing smoke on the next start up. Idling gives the scavenge pumps time to get the oil out of the heads.

[unhcampus]

The oil level was one bar down from full and after one track session I left the track and drove around for 10 minutes at 40 mph to cool the car down. It is odd that mine is the only Boxster at the track with this problem. Confusing.

Does anyone think it could be the piston rings?

[Topless]

Originally Posted by unhcampus

The oil level was one bar down from full and after one track session I left the track and drove around for 10 minutes at 40 mph to cool the car down. It is odd that mine is the only Boxster at the track with this problem. Confusing.

Does anyone think it could be the piston rings?

Rings are possible, or worn valve guides. If the car tends to burn oil between changes it's worthwhile to do a compression check to eliminate possibilities.

[easyc]

get the motorsports AOS... usually doesn't happen til you upgrade your tires.

[unhcampus]

^easyc - I really think it is the AOS but can not get a consensus and no one else at the track is running one. My local Porsche guy has never even heard of the motorsports AOS!!

I am thinking of going with the motorsports AOS and deep sump.

[unhcampus]

After a good leak down test and compression test, switched to Mobile 1 0w40. The problem has gone away.

[b-raddetail]

The same thing happened to me in my 2003 boxster in a tight left hand corner on two different tracks. It would let out a puff of smoke after the corner and then flash the engine light. First time I replaced the AOS but no luck.

The next track day it did it on a tight left corner twice. I started taking that corner a little easier with no problem. A little later on I went through a little quicker and big smoke, very little power and the engine light flashing.

I limped it back to the pits put it on the computer and things were not looking good. I had it towed back to the shop and torn down and it was catastrophic failure in the heads.

One way to check if its the AOS is pull the MAF its super easy and if its oily most likely its the AOS if not its internal.