A puzzle for diagnosticians

JCMcDougall · 09-08-2023, 08:16 PM

About a year ago I acquired a 2007 E91 with 112,000 miles on it. replaced plugs and coils and since it was coding for transfer case oil, the shop I am using for it (german -BMW,Mercedes and hi end sports cars - ferrari, lambo Mclarin, etc) did the transfer case oil change. Since then, I have put about 9k miles on it.
In late July, I noticed was seemed to be an occasional stutter when driving but felt just like rough road. Since then, I have been able to clearly feel a definite stutter after driving for a few miles. Only appears once there has been several miles of driving. Today when my significant other, brought the car to the shop (she works next door), after an hour commute once she was back on city roads, at 40 mph in top gear and 2000 rpm, it felt like the rear end was going to come apart. If you ease off the rpm slightly and then bring it back, the shaking(stutter) goes away. Upping the rpm reduces the issues and when in top gear at 2000 rpm is the worst. At 60 to 80 mph it does not seem to happen. The shop went through driveline from end to end and every part looked absolutely OK. Two of their techs went through it separately and cannot find a cause.
There are no error codes anywhere in the system either.

What is going on? The shop is nonplussed.

The only thing the shop can come up with next is to drain the transfer case and see if there are any metal bits in the oil to indicate that the transfer case is the problem. (Not cheap to have this done). Note that it was changed by them last year (9k miles ago) and there was no indication of a problem in the oil removed.

JCMcDougall · 09-10-2023, 08:31 PM

I am wondering if the transfer case was not properly filled, or they put the wrong oil in the transfer case.

ctuna · 09-10-2023, 08:59 PM

You are only suppose to use the BMW transfer case oil for the Transfer Case.
Also there is a BMW calibration procedure for the Transfer Case that is suppose
to be done after the Transfer Case fluid change.
If the problem is coming from the rear how are you sure it's the transfer box?
There is an xdrive subforum here.

09-08-2023, 08:16 PM	#1
JCMcDougall New Member 0 Rep 16 Posts Drives: BMW 328xi Wagon Join Date: Aug 2022 Location: Ohio iTrader: (0) Garage List 2007 E91 [0.00]	A puzzle for diagnosticians About a year ago I acquired a 2007 E91 with 112,000 miles on it. replaced plugs and coils and since it was coding for transfer case oil, the shop I am using for it (german -BMW,Mercedes and hi end sports cars - ferrari, lambo Mclarin, etc) did the transfer case oil change. Since then, I have put about 9k miles on it. In late July, I noticed was seemed to be an occasional stutter when driving but felt just like rough road. Since then, I have been able to clearly feel a definite stutter after driving for a few miles. Only appears once there has been several miles of driving. Today when my significant other, brought the car to the shop (she works next door), after an hour commute once she was back on city roads, at 40 mph in top gear and 2000 rpm, it felt like the rear end was going to come apart. If you ease off the rpm slightly and then bring it back, the shaking(stutter) goes away. Upping the rpm reduces the issues and when in top gear at 2000 rpm is the worst. At 60 to 80 mph it does not seem to happen. The shop went through driveline from end to end and every part looked absolutely OK. Two of their techs went through it separately and cannot find a cause. There are no error codes anywhere in the system either. What is going on? The shop is nonplussed. The only thing the shop can come up with next is to drain the transfer case and see if there are any metal bits in the oil to indicate that the transfer case is the problem. (Not cheap to have this done). Note that it was changed by them last year (9k miles ago) and there was no indication of a problem in the oil removed.
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09-10-2023, 08:31 PM	#2
JCMcDougall New Member 0 Rep 16 Posts Drives: BMW 328xi Wagon Join Date: Aug 2022 Location: Ohio iTrader: (0) Garage List 2007 E91 [0.00]	I am wondering if the transfer case was not properly filled, or they put the wrong oil in the transfer case.
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09-10-2023, 08:59 PM	#3
ctuna Lieutenant General 1911 Rep 13,104 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	You are only suppose to use the BMW transfer case oil for the Transfer Case. Also there is a BMW calibration procedure for the Transfer Case that is suppose to be done after the Transfer Case fluid change. If the problem is coming from the rear how are you sure it's the transfer box? There is an xdrive subforum here. Last edited by ctuna; 09-10-2023 at 09:05 PM..
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