releasing brakes sometimes causes slight bump
 

Anyone feel that sometimes the car bumps forward when releasing the brake at a red light - sometimes even before you hit the accelerator? I definitely feel it if I go from brake to gas quick - the bump is more harsh - and it's not because my foot is still on the brake at all. This only happens after prolonged complete stops like red lights.

Seems it needs an extra second than normal to release before you touch the gas. Are the brakes somewhat electronically controlled? This is a 3.0si so it's not related to the 4.8i reported rough acceleration.

EDIT>> It might have something to do with the anti-rollback feature if you're slightly uphill... it sticks for an extra second like I said but on a few occasions there's a slight bump forward. And these aren't hills... did they do this as a default configuration then?

*UPDATE*: I brought it in for a bunch of issues and my SA found a service bulletin on this "bump" issue and updated my firmware (I've been looking for an excuse for it anyway). So a day later I got it back and no more bump on brake release.

We have the exact same issue with our 3.0. Only happens periodically... and of course the dealer was unable to replicate when we brought it in. They suggested a software upgrade which we have not done yet.

The first time it happened I thought I was bumped by the car behind me. Curious if anyone else has had the issue and if software resolved it.

Thanks

I think it has to do with the soft-stop feature, I notice this all the time on 3 series loaners, it could also be the hill hold feature

I get this on mine too, not all the time though. I let go of break while the car is stopped and it jerks forward before I get to gas pedal. The anti-rollback is not even activated.

I think you're talking about the Hill-Start assistant, which holds the brakes for 2 seconds if it thinks you're on a hill. Problem is, in parking lots, this is unpredictable.

I happens with mine too. It also shifts the weight forward a little bit when I apply the hand brake and turn off the car. I am planning to ask the dealer to take a look at it during my next service.

That happens all the time on flat surfaces. Interestingly enough, when I'm parked on an incline, it doesn't move at all when I turn off the car. I'll definitely have it looked at whenever I end up going in for service.

All of the above symptoms here also. I thought it has to do with HOLD feature, but it is there even when the HOLD is not active. Please post if any software fix is needed and/or it did solve the issue.

tried a few times today but have not been able to duplicate it. Tried because it's going for the annual workup at the end of the month. BTW, what kind of loaners can we expect? Too much to ask for something like a 335 (wanna feel the twin turbo)?

Don't expect anything better than an Enterprise rental. BMW loaners are for lucky people.