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325i Gearbox Issue? Jerk to stop and accelerate

10K views 11 replies 7 participants last post by  dallas70 
#1 ·
Picked up my 325i last weekend, great car. It's got the Steptronic transmission.

I've done a little bit of searching on this problem and there seem to be conflicting answers.

When I take my foot off the brake of my car it jerks forward and seems to really want to go, and when I stop I'm really having some difficulty doing it smoothly.

I've seen people say that something needs to be reprogrammed? Taking it in to an indy shop down the street next weekend for an oil change so if I can get that done at the same time if it needs to be changed.

I've also seen people indicate that the stock pads are really "sticky" (what? isn't that what they're supposed to do). Or that there may be a problem in the differential.

Any advice? Thanks!
 
#3 ·
Thanks for your response. I did test drive the car; the issue wasn't bad enough for me to notice at the time and still isn't *terrible*, but it's slightly annoying that the car lurches forward when I take my foot off the brake.

I was more curious if anyone had any suggestions as to what it might be (or is it normal behavior?). It is within my means to pay to have my car repaired, please don't mistake this for buyer's remorse. I got an awesome deal on it.
 
#4 ·
I have a feeling that you're brake booster valve needs replacing. It's such a small annoying thing that causes so many random issues with the car. Also have a look at using a gasket sealer to seal the new one properly, it's pretty much faulty brand new in terms of keeping pressure on a lot of cars.
 
#6 ·
Thanks for your response. I feel like the brake pedal would be hard if this was the issue. While it's certainly much harder than my old Grand Prix, it doesn't feel any harder than other cars I've driven. This is provided you're talking about the check valve, not a different one. Might throw a vacuum code too???

If it makes you feel any better, I bought my 325i almost 4 yrs ago as a CPO w/23k miles on it and it has always done what you describe (definitely just a brake pad issue; not differential or brake booster). The brakes are "sticky" just as I come to that last couple of inches to stop or take off from a stop, making it difficult to be completely smooth. I mentioned it to the service guys the first time I took it in for service and was told they're working as designed. I'm still on the original front pads w/about 60k miles and just changed the rear pads and flushed the brake fluid several weeks ago; no difference in braking (changed the fluid a couple of years ago also with no noted performance difference). Great brakes so I can deal with the minor stickiness at a stop. I may consider switching to different front pads (non-OEM) when they're due as you'll find some great recommendations here, but I've been satisfied with the performance.

A longwinded response but in a nutshell - I wouldn't worry about it.

BTW, I've driven a couple of newer 3's as loaners over the years - slightly less brake stickiness than mine but very little difference. It's a design thing. Search the forum for good pad recommendations.
Thanks for your response. This does put my mind at ease a bit; I haven't driven another 3 before but 5's and 6's and they behave rather differently it seems. The OEM brakes do seem stellar so I probably wouldn't look for aftermarket ones; it's just unexpected. I'm coming from a car that's got +120HP/lbft torque and so it's a little strange so have the 325i "launch" itself when I take my foot off the brake.
 
#5 · (Edited)
If it makes you feel any better, I bought my 325i almost 4 yrs ago as a CPO w/23k miles on it and it has always done what you describe (definitely just a brake pad issue; not differential or brake booster). The brakes are "sticky" just as I come to that last couple of inches to stop or take off from a stop, making it difficult to be completely smooth. I mentioned it to the service guys the first time I took it in for service and was told they're working as designed. I'm still on the original front pads w/about 60k miles and just changed the rear pads and flushed the brake fluid several weeks ago; no difference in braking (changed the fluid a couple of years ago also with no noted performance difference). Great brakes so I can deal with the minor stickiness at a stop. I may consider switching to different front pads (non-OEM) when they're due as you'll find some great recommendations here, but I've been satisfied with the performance.

A longwinded response but in a nutshell - I wouldn't worry about it.

BTW, I've driven a couple of newer 3's as loaners over the years - slightly less brake stickiness than mine but very little difference. It's a design thing. Search the forum for good pad recommendations.
 
#8 ·
Shifting

I have the same problem and my service advisor told me since the car was purchased used they may need to reset the computer or memory something to that effect. I am going to get my car back tomorrow so I will let you know if it works, also can let you know exactly what they did if it is fixed.
Thanks,
 
#11 ·
When I take my foot off the brake of my car it jerks forward and seems to really want to go, and when I stop I'm really having some difficulty doing it smoothly.
Define "difficulty stopping smoothly." Is does it feel like the transmission is fighting you?

Because a common problem is that transmissions can be really jerky sometimes. It's actually not the brakes, it's the transmission hunting for the wrong gear at the wrong time, and upsetting the car's motion.

It's relatively easy to test brakes. Get up to short speed, force the transmission into Neutral, then apply braking. With the transmission out of the picture, you should better be able to tell if the brakes are actually sticky.

For what it's worth, I'm not buying the "by design" explanation. Dealers always say that. Brakes should be smooth and progressive; they definitely are in my BMW.
 
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