630i N52B30 cold start ( -10C ) then stall

[everfame]

Hi,

I have a problem with a E63 630i that have the N52B30 engine, in the morning after a cold night I push the Start button, car cranks then immediately dies. I have to give it some throttle right after it starts to prevent it from stalling. If i try to start it multiple times the result is the same, crank, revs to 1200rpm then dies.

This happen only when the temperature is below -8 degree C. If it is warmer, like between -1C and -8C, it will start but after the initial 1200rpm rev it drops to about 300rpm ( nearly stalls ) then it recovers ( very fast ).
If the temperature is above 0C the car starts normally.

Also, no rough idle, if the car starts ( even if I help it with a little throttle ) it runs just fine.

I scan the car, no errors. Only once, about one year ago I did have a Vanos solenoid stuck code that never reappeared.
The battery is new and the car cranks very fast, no hesitation at all.

Thanks !

[aktansrt]

My wife's car has the same issue. It is an X5 but with the same N52B30 engine. The exception is that the ambient temperature can be in the 70s, and the same issue happens. I have replaced the valve cover, although it seemed to help for a while, it is back to the stall again.

The car starts and tecovers after the 2nd or 3rd try though, and rhen runs normal. When warm, the issue is not there, only in cold starts.

Have you had a resolution to this issue? I'd appreciate to know the solution since the car has no error codes - even hidden.