Desperate for help with jerking when accelerating (730d)

miococo · 04-28-2024, 05:36 PM

Sorry for a quite long post, but i am desperate for help, since i cant seem to find the issue.

My car (2009 730d, remapped, 150k miles/250k kms) has an issue when im accelerating from ~1500rpm+ the car starts violently shaking, jerking, and it feels as if the gear slips and catches every second, but the rpm gauge does not jump.
If i keep pressing the pedal this continues, until suddenly the rpm's jump up high and the car continues accelerating normally.

The problem seems also only to occur when the car is warmed up and driven for like 40 minutes. Usually i also get a good 2 accelerations that are normal and after that the issue starts.

Couple times After the shaking and jerking have happened, i have tried to accelerate with D/S mode on, and those accelerations have been normal, allthough i have pressed the accelerator fully during these.

I've also noticed a burning oil like smell, coming from underneath the car (not from engine bay) after driving normally when i have gone home. Havent had the smell after noticing this issue though.

Car drives fine at low speeds.

Im speculating that the problem occurs when the car is using alot of torque, but the acceleration is working fine when starting from a standstill as well, so i dont think the torque would be too much.

For diagnosis i have done:
Changed fuel filter
Checked transmission fluid level and quality.(color is good and does not smell burnt, fluid is only 15k kms old)
Checked for codes (no codes)
Checked injectors with ista (says all ok)
Resetted the transmission adaptations.

Any help is appreciated!

Motolord · Yesterday, 06:12 PM

I believe I have the same problem. Does your car have Xdrive? I've narrowed it down to the Transfer Case. The bumping/jerking is the Transfer Case engaging/disengaging and the power to the front wheels going in and out. I've found references to updating/clearing/reinstalling the transfer case adaptations using a scan tool. I tried that and it did not seem to fix it, but I may not have done it correctly. I'll try again sometime. I've also found references to servicing the Transfer Case Fluid. I did that and it seemed to help some but did not fix it. The next step I'm going to try is changing the control module.

04-28-2024, 05:36 PM	#1
miococo Registered 2 Rep 3 Posts Drives: 730d f01 Join Date: Apr 2024 Location: europe iTrader: (0)	Sorry for a quite long post, but i am desperate for help, since i cant seem to find the issue. My car (2009 730d, remapped, 150k miles/250k kms) has an issue when im accelerating from ~1500rpm+ the car starts violently shaking, jerking, and it feels as if the gear slips and catches every second, but the rpm gauge does not jump. If i keep pressing the pedal this continues, until suddenly the rpm's jump up high and the car continues accelerating normally. The problem seems also only to occur when the car is warmed up and driven for like 40 minutes. Usually i also get a good 2 accelerations that are normal and after that the issue starts. Couple times After the shaking and jerking have happened, i have tried to accelerate with D/S mode on, and those accelerations have been normal, allthough i have pressed the accelerator fully during these. I've also noticed a burning oil like smell, coming from underneath the car (not from engine bay) after driving normally when i have gone home. Havent had the smell after noticing this issue though. Car drives fine at low speeds. Im speculating that the problem occurs when the car is using alot of torque, but the acceleration is working fine when starting from a standstill as well, so i dont think the torque would be too much. For diagnosis i have done: Changed fuel filter Checked transmission fluid level and quality.(color is good and does not smell burnt, fluid is only 15k kms old) Checked for codes (no codes) Checked injectors with ista (says all ok) Resetted the transmission adaptations. Any help is appreciated!
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Yesterday, 06:12 PM	#2
Motolord Registered 0 Rep 2 Posts Drives: '10 F01 750ix '07 E70 X5 4.8i Join Date: May 2024 Location: Maryland, USA iTrader: (0)	I believe I have the same problem. Does your car have Xdrive? I've narrowed it down to the Transfer Case. The bumping/jerking is the Transfer Case engaging/disengaging and the power to the front wheels going in and out. I've found references to updating/clearing/reinstalling the transfer case adaptations using a scan tool. I tried that and it did not seem to fix it, but I may not have done it correctly. I'll try again sometime. I've also found references to servicing the Transfer Case Fluid. I did that and it seemed to help some but did not fix it. The next step I'm going to try is changing the control module.
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