128 transmission seeking/shudder

[arctic128]

Hello,

I searched around and it didn't look like this has been previously covered (not that I could find at least) so I am making a new post.

I am looking for suggestions of how to best proceed with a problem I am experiencing on my 2013 128i coupe, automatic. About 62k miles on the odometer. Out of warranty. A commuter vehicle typically driven 100 miles a day. Typically 20 miles of stop-and-go to slow traffic each way followed by cruise at normal highway speeds. Being in Alaska, the car is fully warmed before driving in winter months and when possible other times.

The problem: At 2-3k RPMs, under constant throttle or light throttle at 20-40 mph I feel a gentle to very strong “pinging” or “seeking” feeling that I think is the transmission. My sense is that it occurs when the car is “on the fence” if it needs to downshift but is otherwise random in occurrence. If I do nothing when this occurs, the seeking/or pinging increases in frequency and intensity resulting in a very strong and concerning shudder. On all but one occasion no check engine (only got that once, recently). Nothing else seems to be wrong. If I force a downshift with the “flappy paddles” the problem resolves immediately. Does not occur at higher RPMs. Most problematic driving surging rush traffic that tends to be slower and require a lot of constant throttle at lower speeds, and occasional downshifts to accommodate traffic conditions.

A bit more history:

Car bought new from local BMW. Around 18k miles, complained that the transmission felt a bit “off” and lazy shifting in 2/3rd gears (especially upshifts which felt a bit hesitant). Dealership did an adaptive transmission reset. Advised nothing else wrong. Seemed to be a bit better, but dealer not responsive to complaint that car felt “off” and indicated that suspension and other systems appeared to be in good order. Car has had good and bad days since, the car usually feels hesitant on shifts and like something is not quite right with the transmission and like the suspension is out of whack somewhere but occasionally had great days.

Regular warranted maintenance performed at dealership but I had an indy shop perform more frequent engine oil changes. Never touched the transmission fluid. Regular tire replacements, alignment etc.

55k+ miles, the car started experiencing the problem described in paragraph 2. But approaching 60k miles it became MUCH more frequent. Owing to a lack of trust in my local dealership (issues with work done on various cars—they seem to want to maintain a lease fleet but not maintain cars) which caused me to part ways with them as much as possible. I had an excellent and trusted local euro shop but sadly they shut down and there is no replacement.

I took the car into another shop that maintains most of the post-warranty euro cars in the area. Took some trying but I clearly re-created the problem for a mechanic on a test drive. They did some research and advised that my issue is addressed in a BMW service bulletin that generally describes transmission seeking/vibration at suburban speeds. After a call to BMW NA, they determined that my vehicle has the metal pan, GM transmission not the “other” plastic panned unit. The bulletin flow chart advised fluid replacement, introduction of some sort of BMW fluid to “rejuvenate” the fluid (I am not sure what there is to rejuvenate if you are doing a replacement?). And application of an item described by a number that they believe is likely a transmission software update because it described driving something like 50 miles after application and evaluating. The shop didn’t have the adapter needed to do a full flush on the transmission, but replaced most of the fluid with OEM, a new filter, and advised that the old fluid was in OK but not terrible shape (I expected to hear something really grim). Car also got a new battery, alignment, and tires. There were no engine codes saved, except a misfire code on one cylinder. The misfire code didn’t surprise me: I got into bad gas once or twice in the past year in the winter and the car had some nasty misfires. They too performed an adaptive transmission reset.

Upon completion, they advised that the problem was not completely resolved, but much improved. I picked up the car and within 150 miles the problem returned and is back to its previous frequency if not worse. The other day it happened and the car threw a code (I got a check engine, but it went out).

This car drives like a dream (precise and confidence inspiring) when it drives well but as indicated above has felt off without explanation most of my ownership.

My questions are:
1. any sense what is wrong?

2. When I ultimately end up at the Dealership, what do I need to tell them about this and what diagnostics should I expect and insist them to perform (they love to plug cars into the computer, say nothing looks wrong and return them . . .that is another reason I parted ways when I had a viable alternative).

3. any credible chance of getting this covered under my [expired] warranty given that I have complained about this car being off and about the transmission most of its warrantied life?

5. is transmission failure at this mileage an outlier or common on this car?

I appreciate any insight you can give