My M4 GTS continues to accelerate after I let my foot off the gas

[Gomeler]

Originally Posted by Schultz28

Sport plus.

Originally Posted by FormulaMMM

Reluctant to question someone's lived experiences, but have to wonder if F8X sport plus throttle setting and this issue are coincidence.

There is no deadzone at the top of the throttle in this setting, it is effectively on/off.

Yeah.. sport+ will continue to feed an absurd amount of throttle if you even breathe on the pedal. Would not recommend driving anywhere in sport+ to be honest.

[h_bakken]

Originally Posted by Gomeler

Yeah.. sport+ will continue to feed an absurd amount of throttle if you even breathe on the pedal. Would not recommend driving anywhere in sport+ to be honest.

I have also noticed in sport plus if I'm trying to takeoff at low to moderate speed and accidentally too much throttle the unexpected acceleration causes my foot to fall back a little bit then unexpected deceleration causes my foot to go forward, and then the car starts to lurch over and over again until I let off or punch the gas. It's the same problem my head in my E92, purely user error.

[the_scotsman]

Originally Posted by h_bakken

I have also noticed in sport plus if I'm trying to takeoff at low to moderate speed and accidentally too much throttle the unexpected acceleration causes my foot to fall back a little bit then unexpected deceleration causes my foot to go forward, and then the car starts to lurch over and over again until I let off or punch the gas. It's the same problem my head in my in 92, purely user error.

BTDT. both in the eE46 and F82

[FormulaMMM]

Originally Posted by h_bakken

I have also noticed in sport plus if I'm trying to takeoff at low to moderate speed and accidentally too much throttle the unexpected acceleration causes my foot to fall back a little bit then unexpected deceleration causes my foot to go forward, and then the car starts to lurch over and over again until I let off or punch the gas. It's the same problem my head in my in 92, purely user error.

The buckin bronco. (Technical term.) It's a good look with wifey in the car.

[4play]

Originally Posted by h_bakken

I have also noticed in sport plus if I'm trying to takeoff at low to moderate speed and accidentally too much throttle the unexpected acceleration causes my foot to fall back a little bit then unexpected deceleration causes my foot to go forward, and then the car starts to lurch over and over again until I let off or punch the gas. It's the same problem my head in my E92, purely user error.

Gotta quickly shift into second when that happens.

My default "M2" setting is Sport Plus on drivetrain and Sport steering, so I've gotten good at the quick upshift to avoid lurching.

[Schultz28]

Originally Posted by FormulaMMM

Reluctant to question someone's lived experiences, but have to wonder if F8X sport plus throttle setting and this issue are coincidence.

There is no deadzone at the top of the throttle in this setting, it is effectively on/off.

I would find an empty road, do the 2nd to 3rd gear pull you detail 10x. Make sure with each one you're fully off the throttle -- as in, snap your foot off the gas like it's on fire.

if you aren't able to replicate the issue, then you might consider "user error" being a potential cause of the prior experience. Again, where user error would be as small as continued slight pressure on the gas when you thought you were fully off.

It’s only happened once so far. Definitely not user error. I pretty much only drive in sport plus and level 3 sport mode. And I have been tuned for 2.5years now. Recently upgraded to pure stage 2 turbos a couple months back and running the OTS map from BM3.

I had removed my foot from the pedal completely and the car still accelerated like I had been full throttle for another 1-2seconds until I tapped the brake which seemed to have cancelled the acceleration. Tripped me the hell out. Just crossing my finger it doesn’t happen again.

[FormulaMMM]

Originally Posted by Schultz28

It’s only happened once so far. Definitely not user error. I pretty much only drive in sport plus and level 3 sport mode. And I have been tuned for 2.5years now. Recently upgraded to pure stage 2 turbos a couple months back and running the OTS map from BM3.

I had removed my foot from the pedal completely and the car still accelerated like I had been full throttle for another 1-2seconds until I tapped the brake which seemed to have cancelled the acceleration. Tripped me the hell out. Just crossing my finger it doesn’t happen again.

Lot of aftermarket variables there. If I were in your shoes, I'd try in earnest to replicate on some open roads to understand if you have a problem.

[PhatLyfe]

Originally Posted by delfunk

Has anyone experienced the car still accelerating once you let your foot off the gas for a couple of seconds under full acceleration? Another GTS owner has verified this with me as well. There are no fault codes and of course and they cant duplicate it. It's always when driving hard from 1-2 gear.

I'm thinking the water injection system is still shooting water and is malfunctioning or a faulty throttle body.

The BMW engineer thinks it's the turbos still spooling and air is getting into the intake. I told him impossible there is a throttle body and a blow off valve. He didn't like hearing that. Maybe the throttle body has an issue?

Had the same mysterious issue last September on my 2018 F83. no codes popped up, but a random fluke of the car acceleration on occasion when stopped at a red light.

I had to jam on the brakes of i was going to plow into the person in the front of me..

People in the forums thought since the brake pedal is so close to the accelerator, i would be pressing it by mistake, that was not the scenario..

Brought the car to the dealer, they saw no codes and try to recreate the scenario, but could not.. they kept the car for 2 days and updated the software and i've not had this issue so far..

Let us know, what they tell you..

[FormulaMMM]

Is there anyone who has experienced this in intentional test conditions??

[Crawford0719]

Originally Posted by FormulaMMM

Is there anyone who has experienced this in intentional test conditions??

I have had this issue on my 2020 ZCP DCT M4 on a few occasions. This sucks btw. Just tested tonight and was able to duplicate my issue with the throttle sticking.

Same back road, Same area, same setting condition.

Always on s2 or s3, doesn't matter sport or sport plus,

Full throttle in second gear, click up to 3rd after top of 2d and the car holds the revs and slightly continues to accelerate and I can't understand why. It won't let me up or down shift for this 2-3 second episode. I hate it. I have had it happen before in a straight line as well. This back road has a lot of trees and turns, I wonder if it has to do with the frontal collision settings possibly? Any input would be appreciated. This is not just a gts specific issue.

[h_bakken]

Originally Posted by Crawford0719

I have had this issue on my 2020 ZCP DCT M4 on a few occasions. This sucks btw. Just tested tonight and was able to duplicate my issue with the throttle sticking.

Same back road, Same area, same setting condition.

Always on s2 or s3, doesn't matter sport or sport plus,

Full throttle in second gear, click up to 3rd after top of 2d and the car holds the revs and slightly continues to accelerate and I can't understand why. It won't let me up or down shift for this 2-3 second episode. I hate it. I have had it happen before in a straight line as well. This back road has a lot of trees and turns, I wonder if it has to do with the frontal collision settings possibly? Any input would be appreciated. This is not just a gts specific issue.

Are you able to reproduce it often? Maybe show the service rep or tech!

[Krummelz]

Just found this thread after my F80 started doing the same thing. It's a DCT. I've had the car about a year now, and only had this happen to me three times, every time on the same stretch of road.

On my way home, doing a 2nd gear pull, shift to 3rd and hit the brakes before turning into my street. (I do this regularly.) I'm not at the limiter when I change gears, but as soon as I shift into 3rd and hit the brakes to slow down, it's like the accelerator gets stuck and the car revs out to redline hitting the limiter for like 2-3 seconds before calming down. The funny thing is, I can see it shows the car is in 3rd gear on the dash, but it's as if the clutch is not engaged while this is happening, so it's not a runaway situation. I am able to slow the car down normally and the accelerator lets off by itself without me doing anything else.

I have had other instances where I do this, but it does feel like the car keeps on going by itself and I have to really mash the brakes to have it slow down. Also on the same stretch of road.

No error codes show up. The dealer can't find anything wrong. The car is stock standard.

The dealer did point out that I had non-BMW Micheline's on the back (no star symbol present) even though they are the same size, and the fronts are a bit worn and almost ready to be replaced. The workshop manager reckons it could be wheel speed differences or something between the front and rear tires with the fronts being worn. Doesn't add up to me.

Anyone happen find any resolution to this yet?