[AndrewC1989]

As the title of the post states, I've experienced some studder or shudder from the car during heavy acceleration. It seems to only happen when flooring it up hills or inclines. Any ideas? No lights or codes. I was thinking maybe the fuel filter? My car is at 67k and last fuel filter was put in at 35k. I inspected the transfer case, changed the flange, fluid, and flex disc at 50k so I'm kind of assuming/hoping it's not transfer case related. Any insight, help, or suggestions would be greatly appreciated.

[opinion914]

May be the clutch within the transfer case. You'll want to run it in RWD only and see if the symptoms go away. There's a fuse you can pull to put it in RWD though I can't remember which -a search will get you that info.
BMW was/is doing recalls on janky TC's.

[AndrewC1989]

Originally Posted by opinion914

May be the clutch within the transfer case. You'll want to run it in RWD only and see if the symptoms go away.

Good idea, I'll try it out

[Enabled]

Does it happen at a specific rpm?

[AndrewC1989]

Originally Posted by Enabled

Does it happen at a specific rpm?

It doesn't happen often enough where I've detected a pattern of any kind, other than it seems to only happen during heavy acceleration and possibly only on inclines. I just went hooning on the highway to try to replicate it and I couldn't do it. The only thing that changed from last time I drove it was that I filled the tank with gas. Could it be possible that the car was fuel starved going up hill WOT? Or is that just my optimistic thinking? I guess I'll have to keep an eye on it and see if it happens again and when it occurs. I had a TDI Jetta back in high school and It would shake under heavy acceleration when the fuel filter was clogged so that was my first guess.

[Enabled]

It wouldn't be a fuel issue at all. These will immediately go into limp mode and throw codes if there is a fuel pressure deviation.


(Although I hope you didn't fill the tank with gas )


I would watch the rpm when/if it happens.

On the higher torque 328d, I've noticed that there is a very specific mid-chassis rumble at around 2500rpm, in 6th or 7th gear. This is on rwd or awd. It seems the higher mileage ones will do it. I attribute this to the driveshaft center support, but I haven't dug enough into it. It's inconsequential.

[AndrewC1989]

Originally Posted by Enabled

I would watch the rpm when/if it happens.

On the higher torque 328d, I've noticed that there is a very specific mid-chassis rumble at around 2500rpm, in 6th or 7th gear. This is on rwd or awd. It seems the higher mileage ones will do it. I attribute this to the driveshaft center support, but I haven't dug enough into it. It's inconsequential.

It happened again today very briefly, WOT going up a slight incline. Could not reproduce on flat area or downhill. Car was in sport mode but transmission was in automatic. As a result I was unable to see what gear I was in (it just showed D) but it must've been 5th or 6th. RPM's were between 3-4K. I was maybe going 90-100. Studder was very subtle but was there. Was using the gear kickdown under the pedal. Will play around with it more to see how to reproduce more consistently.

Things to note: I have a kerma stage 1 tune, I've coded the 2TB sport auto option, and I've coded Sport+ mode in. Not sure if any of these things are relevant but thought I should mention.

[catskillclimber]

You have literally the exact symptoms we had at 50k...transfer case fail

[AndrewC1989]

Originally Posted by catskillclimber

You have literally the exact symptoms we had at 50k...transfer case fail

Guess I should shut it off with xDelete and see if the symptoms are there in RWD.

Assuming it is the xfer case, what would you suggest I do? Is there a way to service it? Do I wait for it to fail and see if dealer will replace?

[catskillclimber]

Originally Posted by AndrewC1989

Guess I should shut it off with xDelete and see if the symptoms are there in RWD.

Assuming it is the xfer case, what would you suggest I do? Is there a way to service it? Do I wait for it to fail and see if dealer will replace?

If your still under warranty, those symptoms are enough for BMW to swap out the transfer case. Do a search in this forum for "transfer case". Look for "ATC 35L rebuild" and "output shaft failure...". Both are excellent threads and will point you to shredded splines on the output shaft. Otherwise it seems like finding a salvage unit or getting a new one from BMW are your only options.

[AndrewC1989]

Originally Posted by catskillclimber

If your still under warranty, those symptoms are enough for BMW to swap out the transfer case. Do a search in this forum for "transfer case". Look for "ATC 35L rebuild" and "output shaft failure...". Both are excellent threads and will point you to shredded splines on the output shaft. Otherwise it seems like finding a salvage unit or getting a new one from BMW are your only options.

I'm out of warranty unfortunately, otherwise I'd already have gone to bmw and had them deal with it. I saw that thread you mentioned about a year ago and changed the fluid, output flange, and flex disc. There was little to no wear on the old flange but I put a brand new one in anyway so that makes me wonder If that's the issue or like another poster above suggested, maybe the clutch inside the xfer case is the more likely the culprit. Guess the first thing I will have to do is disconnect xdrive to narrow it down.

[xcftw]

I had what seems like the same stutter under heavy acceleration, especially uphill. My car had done it forever. Finally started experiencing a clunk when shifting in reverse and my local mechanic told me my guibo was completely worn out and he alerted me to the recall. Took the car to the dealership for the guibo and had them inspect the transfer case. Splines in the transfer case were so worn that the SA was shocked I was still driving it. (LOL)

Car is currently still at the dealership having the work done so no clue yet if it'll fix the issue, but I bet it will! We were already heavily suspecting tcase being the cause as my mechanic had experienced this in other xDrive cars and it went away upon switching to rwd.

[AndrewC1989]

Originally Posted by xcftw

I had what seems like the same stutter under heavy acceleration, especially uphill. My car had done it forever. Finally started experiencing a clunk when shifting in reverse and my local mechanic told me my guibo was completely worn out and he alerted me to the recall. Took the car to the dealership for the guibo and had them inspect the transfer case. Splines in the transfer case were so worn that the SA was shocked I was still driving it. (LOL)

Car is currently still at the dealership having the work done so no clue yet if it'll fix the issue, but I bet it will! We were already heavily suspecting tcase being the cause as my mechanic had experienced this in other xDrive cars and it went away upon switching to rwd.

Good to know. I just purchased xDelete and will be testing today to see if the stutter persists.

Update: all of my symptoms seem to have gone away after putting the car in rear wheel drive. Starting to think it's the transfer case

Not sure if I should bring the car to the dealer yet though. Symptoms are pretty mild still and I have a feeling they'd state nothing is wrong.

[AndrewC1989]

Update: changed wheels and tires almost a month ago and haven't felt it once since. Is it possible that it was related to a bent wheel or uneven tread?

[clemsonf31]

Originally Posted by AndrewC1989

Update: changed wheels and tires almost a month ago and haven't felt it once since. Is it possible that it was related to a bent wheel or uneven tread?

Was your previous setup a staggered setup? Still could be xfer case and sounds identical to the issues I had when mine went out

Max

[AndrewC1989]

Originally Posted by clemsonf31

Was your previous setup a staggered setup? Still could be xfer case and sounds identical to the issues I had when mine went out

Max

Oddly enough my previous set up was squared and I'm staggered now. New set up maintains a 26" diameter so there shouldn't be any issues. Just find it interesting that I haven't felt a single hiccup since swapping wheels and tires where as my symptoms could be felt on a pretty frequent basis with the old ones on. The only other thing that's changed is the weather. Could ambient temperature play a part?

In terms of xfer case maintenance, I changed the flex disc to a rubber one a while back and replaced the output flange (original showed very little wear so was thinking it could be clutch pack wear). I've also been changing the xfer case fluid every other oil change (20k) and that seems to help.

[bigshooter]

Originally Posted by AndrewC1989

Oddly enough my previous set up was squared and I'm staggered now. New set up maintains a 26" diameter so there shouldn't be any issues. Just find it interesting that I haven't felt a single hiccup since swapping wheels and tires where as my symptoms could be felt on a pretty frequent basis with the old ones on. The only other thing that's changed is the weather. Could ambient temperature play a part?

In terms of xfer case maintenance, I changed the flex disc to a rubber one a while back and replaced the output flange (original showed very little wear so was thinking it could be clutch pack wear). I've also been changing the xfer case fluid every other oil change (20k) and that seems to help.

For me it turned out to be my transfer case. The splines were rusting and worn. The entire transfer case was replaced for free under warranty. There is a bulletin on it and you can likely get it replaced free as well. I think up to 120k miles

[AndrewC1989]

Originally Posted by bigshooter

For me it turned out to be my transfer case. The splines were rusting and worn. The entire transfer case was replaced for free under warranty. There is a bulletin on it and you can likely get it replaced free as well. I think up to 120k miles

Good to know. The thing is my splines were fine when I checked and I replaced the output flange anyway, so they're even more fine now. I also don't have a single symptom at the moment so I don't think I'd have much luck replacing anything under warranty right now. If it starts happening again I'll definitely consider a trip to the dealer but as of now there's no point.

[bigshooter]

Originally Posted by AndrewC1989

Good to know. The thing is my splines were fine when I checked and I replaced the output flange anyway, so they're even more fine now. I also don't have a single symptom at the moment so I don't think I'd have much luck replacing anything under warranty right now. If it starts happening again I'll definitely consider a trip to the dealer but as of now there's no point.

I had no symptoms. I brought my car in for a free egr valve. All I had was egr valve code. Occasionally hesitation. Got it back with 10,000 worth of work done for free all under warranty at 100k miles. Biggest ticket item was new transfer case.

[AndrewC1989]

Originally Posted by bigshooter

I had no symptoms. I brought my car in for a free egr valve. All I had was egr valve code. Occasionally hesitation. Got it back with 10,000 worth of work done for free all under warranty at 100k miles. Biggest ticket item was new transfer case.

Last time I brought my car to the dealer (last year) they replaced the valve but I had to pay for it out of pocket. They told me only the egr cooler was covered, not the valve. My cooler passed inspection, the valve did not.