Update, the car is still about the same as yesterday. But, if I come to a stop sign, slow down to about 2MPH and then accelerate, this causes a heavy shudder almost every time.

That's my update for today. Any thoughts would be highly appreciated!

Another update. This is getting very frustrating. The shudder has come back full bore like it was. For two days it was improving to the point of it not even being there. As of today, with no changes whatsoever to anything, including gas, the shudder is back. I don't get how the same car, with the same driving conditions and fuel can change over night like this. My head is going to explode.

I'm thinking maybe this issue is more engine / electrical related now because when this happens, if I press the gas the RPMs drop by about 200rpm and the engine bogs down and the whole car shudders! Then I press a little more and the car snaps to life and accelerated quickly. This is very concerning for traffic conditions since I will be essentially driving up on bumpers and slamming the brakes constantly because of this bogging down and shudder.

Any ideas?

At least it sounds like it's not likely your trans.

Unfortunately you are no closer to a diag. There aren't that many things on the N52 that causes driveability issues but doesn't throw a code. Though your accelerator pedal code, if it is an active code, could be a pointer in the right direction. Have someone drive around while you monitor INPA or ISTA live data to see the throttle duty cycle. See if there are any anomalies.

Emphasis mine

Still not sure what transmission you have, but....

I did this to fix my issues, which were exactly what this video said in the first 90 secs or so (found it after I did the fix lol) and my shudder issues are gone - https://youtu.be/aX0bhui8UXA

I've done a lot of work on mine with very little experience (just lots of confidence :D ) in very expensive areas but never ever ever wanted to touch the transmission. Finally got up the nerve to do it.

**IF** your issue is transmission related, crystalworks advice is the way to go.

Note for future readers: I bought my parts at thectsc.com, they sent everything except for 1 tube seal (they left it out of the order by mistake) but then promptly sent a whole new complete set right away after I let them know (great customer service, even over the weekend, highly recommend).

Great video I just watched it. He didn’t say don’t do it, he did say if you drop the pan and you see a bunch of metal you’re pretty much toast. But, I am leaning towards going for it.

One thing to note, the car felt awful today. It was almost perfect and then today it feels like crap. I got home and I scanned for Codes. There are two new ones. One is A818 RFK PDC invalid data. Another is 2C78 related to the oxygen sensor two after catalytic converter.

I need to look into those two as well. That just happened after the car is been running like trash.

Out of curiosity. How old is your battery? What is the voltage at idle being put out by the alternator?

The battery is at least five years old. I’m heading home now and I’ll load up INPA and check the voltage at idle.

LOL, stop on your way home and buy a battery. I change them religiously at 4-5 years in any BMW.

But seriously, yeah when you get home check the idle voltage. If it's good (13.8+), I'd buy a battery. Might be a good idea to drive around a bit while monitoring the voltage output after buying a battery. Sometimes a failing alternator doesn't present itself at idle. Reset all codes and see how the truck reacts. These things are very sensitive to voltage dips/spikes or not getting enough current from the battery. If you notice anything dipping below 13.6 while driving, your alternator brushes are shot.

^Those issues might not be your shuddering issue, but the EGS in general is very sensitive to voltage/current. Your battery is definitely due for replacement so is an easy thing to start with.

Im using INPA now. At IDLE it’s at 14v exact. When I rev the gas the voltage remains the same. When I let off the gas the voltage dips to 13.7 or so then settles on 14 exactly.

The battery on his laptop is shot so unfortunately I can’t drive around with it I can only do this at home. Do those numbers sound like a bad battery? There is another 95 amp hour battery down the street I can just go pick up for 200 bucks. Since the age of the battery is five years plus maybe it would be a good idea to just do that today. I can use ISTA to register the new battery.

Good, sounds like your alternator is okay. Though driving around and monitoring it would be better confirmation, what you have looks good.

Definitely pick up a battery just as a matter of preventative maintenance. Cooler weather is coming anyway and if that battery is border line, it won't be for long. Was going to ask you if temperatures were falling there when you said the performance tanked after being mostly normal.