[jrmMD]

Here is one I can't find in the forum.

On 3 occasions now, each one after letting the car sit without the engine running until it shuts down iDrive on its own (like in a ferry line), when I restart the car to drive (like to board the ferry), the brakes grab and jerk, and I seem to have limited braking power, at least for a 100 feet or so, or until the engine has run for awhile...

It seems to me this might be an electrical thing, given the running the iDrive/sound/displays off battery for a bit of an extended time preceeds these events, but not sure how that might be the case...

Anyone with thoughts...mine is a '22 X7 M50i...

Thanks in Advance!!

[MystroX5]

So it seems like there isn’t any brake boost clamping down until you get moving?? My X7M50i sits a lot for extended time and haven’t had this backing out of the garage. I have had brake calipers stick to the rotors on my last M2C after applying the e brake when after washing it. It locked the little car up to the point I had to give it a lot of gas and they would pop free but that’s common with wet calipers and e-brake activation over night.

[jrmMD]

Originally Posted by MystroX5

So it seems like there isn’t any brake boost clamping down until you get moving?? My X7M50i sits a lot for extended time and haven’t had this backing out of the garage. I have had brake calipers stick to the rotors on my last M2C after applying the e brake when after washing it. It locked the little car up to the point I had to give it a lot of gas and they would pop free but that’s common with wet calipers and e-brake activation over night.

Yeah, my brakes do the same when I wash it, but this is different, it literally jerks and slows then releases then jerks again, as I push on the brake pedal until it's gone like 100 feet (or the engine has run longer)...in each case I started the car and took right off (like exiting a ferry)

Has never happened, even when letting the car sit for days at a time, only when I've sat in it using battery power

[MystroX5]

Originally Posted by jrmMD

Yeah, my brakes do the same when I wash it, but this is different, it literally jerks and slows then releases then jerks again, as I push on the brake pedal until it's gone like 100 feet (or the engine has run longer)...in each case I started the car and took right off (like exiting a ferry)

Has never happened, even when letting the car sit for days at a time, only when I've sat in it using battery power

You see this happens when you’re on the ferry, is there obstacles around the car perhaps it’s trying to auto break to avoid an obstacle??
We have seen this with people pulling into a real tight garage.

[AlteBMW]

Did you have auto-hold on?

[MystroX5]

Originally Posted by AlteBMW

Did you have auto-hold on?

Very good point. My last G05 X5 would be horribly grabby when it was new when auto hold was activated.

[jrmMD]

Originally Posted by AlteBMW

Did you have auto-hold on?

No auto hold, 2 of 3 times it happened were 1. boarding the ferry, so just in line in a large lot, and pulling forward, then downhill, and the other at a parking lot where I had turned off the car, but left the key and run inside to take care of business, leaving wife in car with radio on, etc. so no notable obstacles for the car to 'see', but all three times car left long enough to turn itself off on its own.

Good ideas, though, thanks for the assistance!!

[jrmMD]

Just adding a post to refresh this thread, wondering if anyone has any other ideas on this topic...