Lerxst

Finally got my car out to our local 1.3 mile track... for a couple of hot laps. It had been in storage for about 6 months, but had been out for about a month of casual driving. This was its first chance to stretch its legs.

Lap one was easy, to warm things up, then I was driving at about 8/10ths for the rest of the session. On the fourth lap, I was a the midpoint down the front straight at WOT with a clean shift from 4th to 5th. Right after the shift, I lost power momentarily, looked in the rear view mirror, and saw a HUGE cloud of smoke behind me. I pulled off the course and into the pits. The car seemed to be running fine, but was spewing smoke out of the exhaust. After a minute of idling and a couple of revs, the smoke cleared and didn't return. I drove the hour-long trip home carefully, with no anomalies in engine temp or oil pressure, and no further smoke.

After I got home, I checked my oil level, and it's definitely down, from a week ago. The car will be sitting and I won't get to change my oil till Wednesday... at which point I'll look for bits of engine.

It appears that a bunch of oil briefly blew by the rings... but I'm just guessing. Can anyone shed some light on what's happened and give me advice on my next steps?

Thank you.

Joe

BlownC2

might be the air oil seperator

Lerxst

Awww man... let me take care of this for myself... DAFS!!! "White Smoke" revealed all sorts of supporting evidence for the air/oil separator. Thanks for the response BlownC2. With the thought of a bad motor in the back of my mind, I got ansy and forgot the first step... :P

jasper

I was at Laguna Seca in my 911 a couple years back and a Cayman running ahead of me did the same thing. I thought he was toast, but nope - he was back the session after that and the one after that.

Two years later I'm at the track in my new-to-me 996 and same as you describe, momentary loss of power - big cloud of smoke. No actual problem with the car though - it ran fine all day long. As an added bonus the car would smoke HUGELY between sessions, when I started it up for the next session specifically.

Maybe it's the AOS...but yeah, they do that.

gota911

Was your oil completely full? If so, there are a lot of reports from other 996/997 and even GT3 owners that if you run high G's in a corner, you may get some oil burn due to oil blow by. Many have reported that th e white smoke issue is eliminated and/or severely diminished by getting you oil level about 1/2 to 3/4 quarts below full.

To avoid the white smoke at the start of the next session, let you car run for 3 to 5 minutes after each session to give the oil a chance to settle back and burn off the blow by oil.

Lerxst

I checked the oil a week ago, and it was half-way up the scale in the dash. After the incident, it's down to the first bar. I autocross the car without issue, but these are sustained turns churning up the oil.

Just checked the throttle body... there's oil in there. So I guess that means the AOS needs to be replaced.

Reading the prior threads on this, some people are recommending the sport AOS for 4X the price of the regular AOS. If the sport one is going to last me a lot longer, then I'm open to the idea... thoughts?

Patrick E

Do a search on this. As I recently posted on another thread, a lot of 996 people recommend this but there are not many who have actually done it. I bought the motorsports AOS and talked to my indy about it (he worked on cup cars and Koni Challenge cars) and I decided against it due to cost. While we could have made it fit, there seemed to a be a lot of costly work involved to get there.

You may want to search the Cayman board as well. I talked with a couple of those guys - it seems like more than a few of them have actually made the change.

Lerxst

Found the comments... thx Patrick.

mike1111

I had the same issue at Roebling, it only happened for one session and never again. As soon as I would get on the straight there would be a cloud of smoked so bad I got blacked flagged.

redridge

does 996.2 have a dip stick?... (not the drivers, but the oil type). I would use that as a reference for oil level bellow full.

+1 on idling before shutting it off.

BillJ

yes on the dipstick. at least one in the engine compartment and proly another one in the drivers seat.

russo

Happened to me as well, also received a black flag. I was so worried that I didn't finish the session. Never happened again.

thorin

Had the exact same issue at mosport last year, but i got my puff of white smoke in between sessions. I'm pretty sure it's due to excessive oil as i'd topped up the night before the trackday.