Explanation for a LARGE puff of smoke on start up....during a track day

[Craiglm68]

Evening all

I attended EVO's 1st Goodwood track day today...apart from the fact there were a few too many cars so people had to wait a while for their 15 min sessions), it was a well run event. Very hot (had to let a lot of air out of the tyres), and a great , challenging track, very enjoyable once I got the hang of it....quite a fast track, and there's nowhere to go if you decided to take a detour!

 

During the day, we were all waiting for our next turn (pic below of us all lining up...probably average 1*15 min run per hour). I started up the car to move along, and there was an almighty puff ( and I mean large!) of white smoke upon startup (thereafter nothing). My 1st thought was Air Oil Separator or similar. I drove to the line up point in the pits area next to the track, turned off, sat there for a while, when I started up again there was a small puff of white smoke (the car was reluctant to start, turned over for several seconds, it happens occasionally when it's hot), then cleared and I completed the next session on track. Car running at normal temperatures, no oil being used etc...all as normal.Thereafter, there was no smoke at all upon start up.

 

Any guesses as to what might cause a large puff of smoke upon start up mid way through a track day?

 

And re the M5 photo below, BMW were there offering 10 min dashes around the track in a variety of thei M cars.....the Competition model I drive has the twin turbo 4.4l....massive power (600 hp+), a great noise, but nimble she was not...you could feel how much she weighed!). Goodyear were also there flogging their latest tyres.  The CS acquitted herself well, hitting 125mph down Lavant,  but there was some impressive machinery on track (ie I got overtaken a LOT 🙂 )

Cheers

[extanker]

probably just the AOS emptying out..........how fresh is the oil.......weight......level 

[Craiglm68]

12 hours ago, extanker said:

probably just the AOS emptying out..........how fresh is the oil.......weight......level 

##Not heard of that happening before. As for oil, 5w/40, serviced about 5 months ago, and she doesn't use a drop . No smoke before or after yesterday.

[Aaron]

Forget the smoke: how does the car drive, how does it feel?

 

If you're not using oil since and it feels fine, then there's nothing worth worrying about.

 

I sometimes get a little smoke when warm starting which clears after 1-2 seconds or so... Then I just drive off

[Craiglm68]

9 hours ago, Aaron said:

Forget the smoke: how does the car drive, how does it feel?

 

If you're not using oil since and it feels fine, then there's nothing worth worrying about.

 

I sometimes get a little smoke when warm starting which clears after 1-2 seconds or so... Then I just drive off

##She drove the same as before; like a charm! No puff today either on start up, so must have been a one off. I used to get those same small puffs occasionally on start up (particularly if not driven for a week or 2), since changing to 5W/40 these have disappeared.

[GlosRich]

I think as long as its a puff and then clears, its not an issue, just a feature of the flat 6.

 

If its constant, then its the AOS.

 

[Porsched eggs]

As above, if it's a puff then clears it's likely oil seep which can happen with flat engines when either the car is standing for a long time or when the car is left briefly when the engine is very hot (oil gets much thinner) and is more like your scenario.

 

If it's smoking constantly I'd book it in to make sure there's no bore scoring.

 

Both my old 986 3.2's did it from time to time, even my OPC told me it was normal.

[Craiglm68]

Cheers all. Nothing since re smoke, I did check with my mechanic  ( Eddie at Silvertune near Christchurch, he's a bit of a legend in the local Porsche maintenance circles), he suggested a bit of oil possibly slopped over in the AOS during hard cornering (and there is the chicane just before you hit the straight/pits entrance), which burnt off when next started. Either way, harmless.