Engine shifts down when i floor it sometimes
 

well to be honest there is quite a few problems with my x5.
But today when i floored it (not kick down)....was at a junction...
i noticed that the car just went down a gear by itself with a bit of grey smoke out the bum (the kind you sometimes get when you do a cold start, but in this case the engine was nice and warm)!

(at which point i took my foot of the accelerator)...
It seems to be running fine right now....
there is no warning lights etc.....

do you think its a major tranny issue or an engine issue?
:stickpoke

Im currently making a list of problems for the repair guys anyway :) so might as well add another one!

I just looked at your avatar and I guess you have the pre-facelift (2001-2003) X5. It is a known fact (even a dealer told me) that the 5 speed gearbox can cause problems.

We have the same problem with a 2002 X5 3.0d here. The car makes unneccessary revs and shifting is not smooth anymore. And the funny thing is that we have a same grey smoke coming out the bum as well (even when the engine is warm).

So perhaps you need to replace the gearbox. But I am not a technician or something, so asking other experienced members or the dealer is your best bet.

Good luck!

WOW I HAVE THE SAME PROBLEM I WAS TRYING TO PASS THIS LOSER ON THE STREET AND WHEN I PUSHED THE GAS DOWN HARD TO GO AROUND THE CAR CHOCKED IT FELT LIKE WHAT YOU SAID I THOUGH IT WAS CAUSE I WAS REALLY LOW ON GAS AND THE GAS DIDNT REACH THE PUMP ON TIME BUT NOW I SEE LOTS OF PEOPLE HAVING THIS PROBLEM TIME FOR DEALER AGAIN