Bucking when engine is cold

[ACHTUNG]

I have a 1989 325i. When the outside temp is aprox below 35 degrees, I start the car up and always let the motor warm up for aprox. 2-5 min. before driving.

The car starts to buck when I start to drive. Once the engine is totally warmed up, the bucking stops. What could cause this? how do I fix it?

Thanks!

[MikeE30325i]

you cant. it is just how the car drives when it is cold. its just natural.

[ACHTUNG]

you cant. it is just how the car drives when it is cold. its just natural.

How is this "natural?" It just started doing it this winter. If it was natural, all of our cars would be bucking when cold.

[brandondan1]

Did you hit the secret "Rodeo" switch?

It may be a fuel issue. I would replace the fpr and spark plugs if you haven't in a while.

[MikeE30325i]

How is this "natural?" It just started doing it this winter. If it was natural, all of our cars would be bucking when cold.

my car hesitates and bucks when the engine is cold. but as soon as the engine temp gets higher, and the idle goes down to 600 rpms, the bucking goes away.

it could be that the oil isnt warm enough and covering all the parts of the engine like it should, and maybe parts are rubbing or something, causing the bucking. good luck trying to fix it.

[NC325iC]

my engine gets a very slight hesitation when its cold, but only sometimes, so far it hasnt worried me cause its not real bad right now

[jlevie]

A cold engine requires a richer mixture and even a small intake leak can lean out the mixture enough to cause problems. That would be the place to start in solving this problem.

[ACHTUNG]

A cold engine requires a richer mixture and even a small intake leak can lean out the mixture enough to cause problems. That would be the place to start in solving this problem.

I'll start with that. Thanks.

[asubimmer]

you cant. it is just how the car drives when it is cold. its just natural.

[porsche gt1]

I have the same problem. I do not have a leak in my intake or anywhere else (i know this as I just replaced all my gaskets 2 months ago).

[HST]

This hapened on my E39 this winter, it was an intake leak, I did the valve covers, manifold, and throttle body gaskets, then every vacuum hose I could find. I also replaced every hoseclamp that was on every vacuum hose.