E90 m3 dct not staying in gear

[accarter]

The past 2 days I’ve had some weird DCT issues which led to me being towed this morning. My m3 has never had a transmission issue, but the other day I got 2 warning codes during a very short casual drive:

• 5A54: Transmission overheating: Phase Black
• 5A53: Transmission overheating: Phase Red

The I drive popped up warnings but the car felt normal to me, maybe it was possibly short shifting but hard to tell.

Then today, during a similar drive, I got the same warnings again, but this time followed with extremely slow shifts, and very jerky behavior coming from a stop back into gear. It definitely was having issues when the clutch is supposed to slip into first.

Then I got to a light on a hill. and the car would attempt 1st gear, jerk a lot, and revs fly up as if in neutral.

I got towed, let the car cool off on my street, and then an hour later was able to drive it up my (very steep) driveway.

After looking under the car, my dct pans were wet, and the felt under tray looked pretty gross. BUT keep in mind, this car has never left a spot in my garage.

I’m hoping I just need to do a dct service, but I’ve seen enough nightmare stories related to those codes that were never resolved. Any insight would be appreciated!

[mikerunt]

If the pans were wet I’d imagine they’re leaking and you have low fluid. The DCT is very sensitive to fluid amount. Start there.

[yardbro]

Originally Posted by mikerunt

If the pans were wet I’d imagine they’re leaking and you have low fluid. The DCT is very sensitive to fluid amount. Start there.

+1. This is definitely the place to start.

Keep in mind that just because the car doesn't leave a spot on your garage floor doesn't mean that its not leaking some type of fluid. With this car in particular, the felt trays are notorious for absorbing a massive amount of oil and coolant before you will see any spots on the ground. This is especially true with a DCT pan leak if you still have the cover attached underneath it.

[spammysammich]

The tray actually helps to create slip stream that will blow pooled transmission oil in the cover down the exhaust pipes.

[accarter]

Awesome thanks everyone. I have some parts on order to do the dct service. Will update if this fixes it!

[accarter]

Does anyone know if you need to pull the transmission in order to replace the side pan gasket? Super tight in there but I’m hoping I can sag down the transmission by removing the trans brace and reach those bolts. Would appreciate any advice

[accarter]

Update. Here’s what I did, pulled the trans and addressed all the issues. I made a video if anyone wants to see. Everything fixed. DCT was low by 1.5L, then I added an additional liter by doing a poor man’s GTS overfill procedure

https://www.instagram.com/reel/DAmJ_...RlODBiNWFlZA==

[yardbro]

Originally Posted by accarter

Update. Here’s what I did, pulled the trans and addressed all the issues. I made a video if anyone wants to see. Everything fixed. DCT was low by 1.5L, then I added an additional liter by doing a poor man’s GTS overfill procedure

https://www.instagram.com/reel/DAmJ_...RlODBiNWFlZA==

Awesome dude this is super cool and will probably help some people out in the future who run into something similar. Glad its fixed and working properly now. Thanks for sharing!

[spammysammich]

1.5L low if it is not leaking suggests whoever serviced it did not follow the TIS instructions for refill. This is about what I was able to add by doing the proper procedure. I actually added about 2L because of my Fall Line pan if I recall correctly.

[accarter]

Originally Posted by spammysammich

1.5L low if it is not leaking suggests whoever serviced it did not follow the TIS instructions for refill. This is about what I was able to add by doing the proper procedure. I actually added about 2L because of my Fall Line pan if I recall correctly.

It was definitely leaking, albeit a slow leak that was being absorbed over time from that felt pan. I’d kinda be surprised if the dct had been serviced previously, but who knows 🤷‍♂️

Also there was for sure spillage on the garage floor. So maybe it was closer to 1L short lol.

[spammysammich]

The o-ring for my pressure filter had gone plastic and flat so it would piss out at least a tablespoon of pentosin every start up until the transmission would heat up enough to somewhat seal itself. When I would pull away from a parking spot the puddle that formed in my pan would dribble out and leave a trail of fluid. Typical BMW

[Helmsman]

Originally Posted by accarter

Update. Here’s what I did, pulled the trans and addressed all the issues. I made a video if anyone wants to see. Everything fixed. DCT was low by 1.5L, then I added an additional liter by doing a poor man’s GTS overfill procedure

https://www.instagram.com/reel/DAmJ_...RlODBiNWFlZA==

Nice job, and video!

Shop will bring my DCT down next week (sensor replacement), will ask them to replace that top side o-ring while there.

[Helmsman]

Originally Posted by accarter

Update. Here’s what I did, pulled the trans and addressed all the issues. I made a video if anyone wants to see. Everything fixed. DCT was low by 1.5L, then I added an additional liter by doing a poor man’s GTS overfill procedure

https://www.instagram.com/reel/DAmJ_...RlODBiNWFlZA==

Btw, do you by any chance have the oe part no for that top o-ring mate? (Doesn't show on Realoen of some reason).

Thanks

Edit: Found it (28607849555 right?). First thing one go blind on is the eyes...:-)

[accarter]

Originally Posted by Helmsman

Btw, do you by any chance have the oe part no for that top o-ring mate? (Doesn't show on Realoen of some reason).

Thanks

Sure thing Helmsman here it is 28607849555