Smoke from the back 645ci

Hey guys I have a 05 645, and if I'm stopped for more than a minute and then hit the gas I get massive amounts of smoke coming from the exhaust if I'm already driving and gas it hard it doesn't happen it's only when the car is stopped for a bit of time, no check engine light or any emergency errors have popped up on the screen, I'm afraid to take it to the dealer !! Any ideas of what's going on and how much I'm lookin at?

Maybe valve stem oil seals?

Someone mentioned something about guide valve seals? Or gas valve... I have no idea anyway is that bad?!

Valve seals are probably the culprit's, but change the 2 CCV valves on the valve covers 1st. I think that they cost somewhere around 25.00 each, & will install in 15 to 30 minutes. You can do these yourself fairly easy. There is probably a DIY in the DIY section. If the valve seals are failing, replacement cost in around 3K. There is a lot of info on the 7 series forum concerning this problem.

Good Luck!

What color smoke? White? Black/Gray? Different issue for different color smoke.

Also are you hard accelerating when this happens?

Have you checked your coolant level/oil level lately? (again need to know color the smoke is) either of them down?

I have the same problem...I moved my rear veiw mirror, can't see the rearview, it fix the problem; real cheap like

LOL! Perfect solution !!!

It's black/ grey smoke

I love this car like crazy, I test drove all kinds of cars and can't find the one that will take me away from this madness, I LOVE MY CAR, it is in a class all by itself...I'm buying a 2010 650i convertible in January...It's $10,000 cheaper (winter time baby!!).

I'm about to trade in for the new Mercedes cl550 if this smoke problem is a huge issue

Cars are cheaper during the winter??

Convertibles are...

Could be oil burning or possibly engine dumping fuel into the motor at idle. Check your oil level. But need to take it to a pro for diagnosis at this point.

Oil burning could make sense, my oil level is always low and I end up topping it off about once every 2 weeks

that's pretty excessive oil use....

So get rid of the car huh?

If you are adding oil every 2 weeks then I would say you are having a seal issue. unfortunately you would have to have this checked to find out. Us here trying to diagnose your problem is not going to work for you. But we can be sure that it's an oil burning problem. Could be valve seal, head gasket, who knows. Don't give up on it until you get some feed back from a good indy shop.

This is happening with my 4.4 X5 too. However, it only happens once in a while. Once or twice a week or so. My indy says valve seals. I don't understand why it is not more consistent. Have not obseved this on my 645 and it has 30K more miles.