2006 Cayenne S, well maintained, 122kmiles.
On startup this morning, loud pop and then a billow of white smoke out both exhaust tips. Continues to produce white smoke proportional to RPM.

I did not drive it.
Smells like coolant and/or oil.

Car was just into private P-specialist I use for several P cars; regular service; he did not note anything.

Thinking head gasket or coolant tubes (again - replaced at 80k)???

Thoughts?
Cost?
Drivable to mechanic? (it is a 26 mile, 1 hour drive; dealer is much closer) or flatbed?

Thanks
db

 

Flatbed.

 

I wouldn't drive it.

It's not likely to be coolant pipes again. It certainly could be a head gasket.

Good luck.

 

No brainer. If you drive it and it overheats - serious expense. However, since you have numerous P's, you already know this. I wouldn't drive anything that "went pop" and had any unusual exhaust or noise. Flatbed is the answer I would choose.

 

What colour is your oil?

 

lighter Medium coffee brown (it was just changed a week ago - Mobile 1)

 

Check your air oil seperator, not sure if the Cayenne S has one, but I had a problem with the one on my Cayman S, and in my research found that it can be a source of oil burning. It sucks oil from the sump and feeds it into the manifold. Quick way to check is to remove the oil filler cap while the engine is running , smoking will stop if the air oil separator is the problem. Once again, I had the problem on my Cayman S, so not sure if the Cayenne even has one!

Darryl

 

I tried removing the filler cap while idling (and producing white smoke); the smoke did not stop, got a little worse; then after a few seconds the engine started making a stuttering noise at which point I turned it off.

 

On my Cayman, she would stutter a little when the cap was removed, then the revs would start to rise, I would put the cap back on when she reached about 3000rpm at which point the she would return to normal idle. There may already be a lot of oil in the separator so the smoking may not stop imediately

You could also temporarily disconnect and block the pipes to the air oil separator.
I would exhaust the possibility of it being the air oil separator before looking elsewhere, as it is a cheap fix (about $100) but has the symptoms of something much more severe.

 

Dealer has the car.
No smoke last night, fluid full, pressure test passed.
This morning, no smoke, doing pressure test one more time.

Realized the car was washed just prior to the first start with the smoke. Could this just be residual water from the washing evaporating as the engine/exhaust heats up the water remaining in the exhaust system? Since I did not run it for any extended time after seeing the smoke, the water did not have a chance to dissipate until getting to the dealer? (we did not intentionally spray water into the exhaust, but the back end was cleaned with a pressure washer and it is certainly possible that water was sprayed into the exhaust).

db

 

....and the loud pop?

 

Not likely. Since the dealer has the vehicle you should know soon.