[FdisFingF10]

2011 535i

I had, what I thought, (But knew was not) an isolated incident where I'm cruising in 8th and 70-75 and the trans pops out of gear per se. It still displays it to be in 8th gear but it is non responsive. I then have to pull over and power cycle and it can be driven again.

2nd time it happened in 8th but when I pulled over it dropped to 4th and the gear indicator on the dash kept changing. I put it in P, then D and resumed driving.

So, I stopped driving the vehicle and did a transmission fluid change with OEM pan and that did not help anything.

When it happens it is bucking the whole time under light throttle which I thought was a separate issue but now I know it is the transmission. I started to do experiments and when the trans is cold, it drives like butter. As it warms up it start to buck ever so slightly and then it makes this thud and I lose the ability to accelerate and I coast to a stop. Under "normal" operation it has a ever so slight slip from stop to take off and 1-2.

It FEELS as if the Torque converter was losing lockup after heat. These transmission are extremely tough as at work we race and abuse many 8HP cars and only my 535i makes me want to burn it. It has 73,000 miles and other than a trans replacement which I will not do since the vehicle value is so low, I was hoping for shared knowledge to give me a warm and fuzzy about dropping more parts in it haha.

The ONLY codes I get repeatedly are:

0xCF19C1 - Message-Group 3 error: Message missing, Receiver: EGS FA-CAN, Sender KOMBI FA-CAN

and

0xCF20C1 - Message-Group 3 error: Message missing, Receiver: EGS FA-CAN, Sender CAS/Fem/JBBF/FRM FA-CAN

QCP is as Follows:

A -118 mbar
B -98 mbar
C 366 mbar
D -37 mbar
E 264 mbar

QCT is as follows:

A 16 ms
B 12 ms
c 7 ms
d -5ms
e 8ms

[95blkmax]

what was the condition of the fluid when you replaced it? I ask because although I've NEVER ran into it on an F10, other cars I've heard cases of coolant contamination due to a faulty trans fluid cooler/ heat exchanger.

[ezaircon4jc]

My best guess is the solenoids...

I know it's the 6-speed, but the procedure should be the same... I believe


YMMV

[beegeezy]

This is for your 2011 535i, right? BTW, you should change your profile car or mention it so you get better info when posting threads/asking questions.

I know you said you wouldn't replace the transmission, but you know you can get a low-mile used 8HP for like $750, right? https://www.car-part.com/cgi-bin/sea...erPage=1&iKey=

[FdisFingF10]

Originally Posted by beegeezy

This is for your 2011 535i, right? BTW, you should change your profile car or mention it so you get better info when posting threads/asking questions.

I know you said you wouldn't replace the transmission, but you know you can get a low-mile used 8HP for like $750, right? https://www.car-part.com/cgi-bin/sea...erPage=1&iKey=

Derrrrp thanks that was a dumb omission by me. Fixing now. I didn't for a second even remotely think a used trans would ever be that cheap so I didn't bother.

I definitely am considering it now. Thanks buddy.

[FdisFingF10]

Originally Posted by 95blkmax

what was the condition of the fluid when you replaced it? I ask because although I've NEVER ran into it on an F10, other cars I've heard cases of coolant contamination due to a faulty trans fluid cooler/ heat exchanger.

Fluid was good the first, 2nd and 3rd time. I did OEM, Liquimoly then OEM again but went from OEM pan to Vaico to OEM pan.

I considered the TCM as well.

[FdisFingF10]

Well, I dropped the trans and it seemed to have dents in several places as if it were serviced before and fell. I found one very clean but large enough piece of metal sheared from somewhere.

Located a trans locally from the site BeeGeezy posted and I swapped it in my driveway a couple weeks ago. Car runs good and actually significantly better. Which showed the trans had issues that were deeper than I noticed.

New trans had 31,000 miles. My solenoids had 100 miles or so. Swapped or Mech and its all gravy, Replaced the aluminum bolts with the steel ones.

Thanks Fellas, until next time.

[95blkmax]

WOOHOO! glad to hear that!