abh11570

yesterday while starting up the engine, I looked into the rear view mirror and saw a large puff of grey smoke. I jumped out and saw that it had come out of the exhausts. I revved the engine, but no more smoke. I switched off, and restarted and no smoke.

Its happened once before, but I reckoned it was just bad gasoline. The cars going for service soon, but just wondering if anyone has experienced this. When it happened before, I did the same thing I mentioned in paragraph 1.

Both times it has happened, I used Premium Gas from 7-11. Its happened twice in almost 4000miles.

I'd appreciate any ideas, before I go in for service.

srknutson

My advice would be to stay away from 7-11!

abh11570

Definately, I did. Last week I was in Orlando, and running empty. By chance I had to fill at a 7-11. No problems throughtout the week, and yesterday, at half tank, I experience this again. I am getting a feeling that it may not be the gas. However, no fillups at 7-11 again, period. Regardless of different towns.

sprink49

Sounds like valve guide seals...mention it to your service advisor.

meegle

Check your anti-freeze to see if it's low as it could be a leaking head gasket. You will normally see grey smoke if water/antifreeze is mixing in the combustion chamber while blue smoke tends to indicate oil issues(guides, rings, etc).

Also you didn't mention if the smoke was during acceleration which can also dictate detonation(as well as emit the "death rattle" sound from the engine) which would be odd if the NOx sensors work properly working.

02S430

thats sucks thats its on the new car, but atleast it under warranty!

E552006

Grey would indicate catalyst substrate. (Pieces of your catalytic converter dislodging, maybe from your sulfur content in the fuel) I would say, nothing to worry about, oil and coolant burn white/blue. Rich condition is black smoke.

abh11570

Could that explain that this large puff at startup, has happened exactly twice in 4000miles?

The puff is large enough that it can be seen from the rear view mirror.

I'm a bit worried, because I am certain it is "grey" in color. Sometimes light blue can be mistaken for grey. If it was the oil or coolant, would you say it would happen more frequently?

The car is going for service next week.