2015 F15 50i - Hesitation/Stuttering Low RPM's

[Goodfella10]

I am looking for some assistance. I've done a bit of reading and searching which has led me to some of the services that were performed below but the issue persists.

Currently, I drive a 2015 F15 50i stock ~136k miles.

I've been encountering this issue for some time now, when driving (seems to be more noticeable uphill) and in the lower RPM range of 1500-3500 and I apply a bit of acceleration not much at all the car seems to hesitate and stutter a bit.
It has gotten to the point where I can intentionally (40% success rate) trigger a drivetrain malfunction error/code. The codes that the car throws seem to range. I will share some below.

Services Performed
1) Spark Plugs
2) Coils
3) PVC ventilation pipes (I believe these had an extended warranty at one point which I missed out on, ordered aftermarket ones when mine cracked).
4) Intake charge pipe (BMW Rubber Boot 1-8 (BMW-13717638568(9)) - passenger side was cracked so I replaced both.
5) All fluids (Transmission, Transfer case, Differential)
6) Passenger side High-Pressure Fuel Pump (This may not have needed to be changed, but reading the forums I had one value ISTA was not reading on the passenger side)
7) Air Intake Filters


I have not done a complete smoke test for air leaks.
I question the quality of fuel in my area (ISTA shows medium quality I believe)

I do have access to ISTA and can run any diagnostics you would recommend, I may just need some guidance since ISTA is fairly new to me.
I've already performed the injector tests, pressure tests, wastegate, and a few others.


These were thrown the other day when both charge pipes were replaced, I cleared the codes and these did not come back just the ones below.



Here is the most recent code(s) it threw this evening (intentionally).



Any guidance or assistance would be helpful.

[Edwardsc1]

One thing I would check, and this may have nothing to do with your issue, but I would get your transfer case fluid changed, and have the clutches reset. If your fluid is old and hasn't been replaces in the last 30/50k miles, that could very well be what's causing your issue. That was the issue when I bought my '15 50i with around 65k on it, same type of shuddering/ loss of power/ shaking from the front end when accelerating. As soon as they did that service, it was perfectly fine.

From what I understand, when that gear oil gets old and dirty, and the clutches adaptations need to be reset, that causes the shuddering, and then the car will cut power briefly to avoid damage to the TC. I'm no mechanic by any means, but that's what I've surmised from my experience.

I doubt this has anything to do with your misfire codes, so again this may not solve your issues at all, but just thought I'd throw that out there. Best of luck to you!

[shimmy23]

Originally Posted by Edwardsc1

One thing I would check, and this may have nothing to do with your issue, but I would get your transfer case fluid changed, and have the clutches reset. If your fluid is old and hasn't been replaces in the last 30/50k miles, that could very well be what's causing your issue. That was the issue when I bought my '15 50i with around 65k on it, same type of shuddering/ loss of power/ shaking from the front end when accelerating. As soon as they did that service, it was perfectly fine.

From what I understand, when that gear oil gets old and dirty, and the clutches adaptations need to be reset, that causes the shuddering, and then the car will cut power briefly to avoid damage to the TC. I'm no mechanic by any means, but that's what I've surmised from my experience.

I doubt this has anything to do with your misfire codes, so again this may not solve your issues at all, but just thought I'd throw that out there. Best of luck to you!

He mentions that he's done TC, transmission and differential fluids already.

OP, at this point, have you taken it to a BMW shop? You're spending some coin on things that haven't fixed the issue. It may be time to take it in

[Goodfella10]

Originally Posted by Edwardsc1

One thing I would check, and this may have nothing to do with your issue, but I would get your transfer case fluid changed, and have the clutches reset. If your fluid is old and hasn't been replaces in the last 30/50k miles, that could very well be what's causing your issue. That was the issue when I bought my '15 50i with around 65k on it, same type of shuddering/ loss of power/ shaking from the front end when accelerating. As soon as they did that service, it was perfectly fine.

From what I understand, when that gear oil gets old and dirty, and the clutches adaptations need to be reset, that causes the shuddering, and then the car will cut power briefly to avoid damage to the TC. I'm no mechanic by any means, but that's what I've surmised from my experience.

I doubt this has anything to do with your misfire codes, so again this may not solve your issues at all, but just thought I'd throw that out there. Best of luck to you!

Thanks for the input. I have already had the TC flushed and recalibrated Maybe I could give it another recalibration.

Originally Posted by shimmy23

He mentions that he's done TC, transmission and differential fluids already.

OP, at this point, have you taken it to a BMW shop? You're spending some coin on things that haven't fixed the issue. It may be time to take it in

Thats the plan now. A lot of the services I performed were coming due anyways (regular maintenance).

Thanks for the input.



Just an update - I did come across a few mentions of the VANOS so I used ISTA to perform the tests and test results came back ok.

[Edwardsc1]

Whoops, not sure how I missed that
Sorry I wasn’t any help!