JEDIKN8

I've searched and read all over the forum but couldn't find anyone else with a similar problem: I've got a 2008 535i with SA and about half the time when I come to a complete stop then begin to accelerate, the car has a sudden jolt as if I got hit from behind. Sometimes it will even roll backwards slightly before the slam happens. I know there have been problems people have been having with the slam when coming to a stop, but mine happens after my stop and when I let go of the brake to hit the gas. Anyone know if this is a normal thing or if it is a problem with just mine? Any ideas on what the problem may be? Thanks in advance!

SLORider

I've got a theory.
Just try this out.
Our cars have this hill holder thing built into the programming of the engine/transmission. The idea is that if your on a hill you can take your right foot off the brake and move to the gas and the car holds itself on the hill for 2 seconds. (we are now to dumb to use our left foot or that funny lever by our right hip)
This is where it relates to your problem; I had the same thing going on as you do. I realized that in some of my stops I don't really have much pressure on the brake pedal. I just cruise to a complete stop. have light brake pressure on a level surface to hold the car, to to take off and then- hesitate, jerk, maybe roll back and then go.
What I started doing was putting more brake pressure on the pedal when stopped, and... the problem went away.

Theory being-when we stop and don't have enough pressure on the brake pedal the car goes into 'hill hold' mode, or tries to, you give it gas and it gets all confused because it has no hill to hold against and it doesn't know whether to go forward, back or stop. Hence the grab, roll back, jerk forward.
Ain't technology great.

Please, try a firmer foot on the pedal and let me know your results.

EBMCS03

Thats an interesting theory... I'm curious to know the results myself.

HotLap

I think it's probably just the auto tranny brain thinking too much...these modern auto trannys are pretty complex now - their programming sometimes is not "quick" enough for the real world situation and it takes a second or two for it to choose the right response thus causing jerky operation. etc. My Lincoln LS did strange things every once in a while - especially confusing for it was when I would be slowing for a red light, almost to a stop, then if the light turned green and I reapplied the throttle, the transmissions control computer would be confused and hesitate before going into 1st with a bang. Had it checked and nothing wrong - just a situation where an instant response was needed and it was a bit slow on the uptake....I've felt this kind of thing in several different of the newer "smart" automatics. I'd have it checked by your dealer, but it may just be something you will have to live with.

Good Luck

elyk

I would try the '25secs trick', not sure it would work but give it a go

http://forums.e60.net/index.php?showtopic=40018

SLORider

By all means do the 25 sec. fix. I have. It works. But it's a different issue.

You need to try this.

Casper

You should've bought a 550i, 535i has too many bugs! and thst is when new, wait a couple of years until the engine blows due to overheating. Trade up while you still can!

SLORider