Martin525i

Willing to throw some money at the car to see if something will fix it. The dealership cannot Duplicate the problem and they have had it a week. No codes, no lights.
Driving me bonkers and am willing to throw some parts ath the car to see if it fixes it.If not I amy trade outside of BMW,

At present when this occurs the car lunges when you put it in gear and will return to normal and lunge again.

turboawd

does it lunge with the ac off?

Martin525i

I leave it the climate control in auto so the a/c is always on.
You have an idea?

turboawd

turn the ac off and see if the problem goes away.

i'm not sure which ac compressor came on your 525, but it could be your car lunges everytime the compressor kicks on. the car is programmed to idle higher everytime the ac kicks on. now if your car has the variable compressor like i know my 550 does, then you shouldnt really have lunging going on, at least due to the ac kicking on.

Martin525i

Does the compressor always kick in when the climate control is in automatic? Seems like I read that the compressor will run on a low settingeven when not needed for cooling to control humidity/fogging of windows? It kicks in stronger when it is needed for cooling?
think this could be why it only does it sometimes?

turboawd

i'm not sure which models have the variable ac compressor, and yes they are usually on at least a little. but i would just turn off the ac next time you get the lunging to eliminate that as a cause.

also, maybe you could do something simple like cleaning your maf sensor with a spray cleaner.

Martin525i

I did clean the MAf SENSOR. The a/c sounds like it could be the culprit. When at the dealer it is parked inside climate controlled. @ home not. could explain why it does it here and not there.