[Unspec]

I seem to be leaking a tiny bit of transmission fluid, but I'm almost 99% sure it's not the pan gasket. I changed it probably about 3 months ago and followed the tightening sequence for the pan to a T, unless it's just a bad gasket but I really doubt. The stuff on the pan looks and feels more like residue, so it doesn't seem be leaking badly, but I'm still bit concerned. Where might it possibly be leaking from? I'll probably take it to the dealer if I can't figure it out, but I'd like to avoid that if I can.




Where it seems to be coming from, with some residue up above on the transmission housing itself




Residue outlined, with blue arrow pointing at the location of the previous picture

I also occasionally get a slight whiff of ATF smell after driving the car for a bit, but it's pretty intermittent and dissipates quickly. Is this normal?

[chipguy]

Did you clean the mating surfaces before you put the pan back?

[ezaircon4jc]

Originally Posted by chipguy

Did you clean the mating surfaces before you put the pan back?

Yes... unless you want a leak.

[SWFLf10]

Hard to tell from the pictures. Could it possibly be a leaking mechatronics sealing sleeve? The part where the cable connects to the transmission. I believe most people usually replace that at the same time as the pan since it's know to leak once it gets older and the seal starts to wear out.

[Unspec]

Originally Posted by chipguy

Did you clean the mating surfaces before you put the pan back?

Yup, wiped the entire surface down with some brake clean and elbow grease.

Originally Posted by SWFLf10

Hard to tell from the pictures. Could it possibly be a leaking mechatronics sealing sleeve? The part where the cable connects to the transmission. I believe most people usually replace that at the same time as the pan since it's know to leak once it gets older and the seal starts to wear out.

I don't think so, mostly because the mechatronics sealing sleeve is very far off to the passenger side, but the leak looks to be coming from the center-ish. I mean, it might be the sleeve, but I'm hoping it's not because for xDrive you have to drop the transfer case to get at the sealing sleeve...

Someone somewhere said there's an overfill vent, but I don't remember ever reading about such a thing. He might be confusing it with the fill port? Dunno.

[chipguy]

Originally Posted by Unspec

Yup, wiped the entire surface down with some brake clean and elbow grease.



I don't think so, mostly because the mechatronics sealing sleeve is very far off to the passenger side, but the leak looks to be coming from the center-ish. I mean, it might be the sleeve, but I'm hoping it's not because for xDrive you have to drop the transfer case to get at the sealing sleeve...

Someone somewhere said there's an overfill vent, but I don't remember ever reading about such a thing. He might be confusing it with the fill port? Dunno.

https://bmwtechnician.com/2018/07/12...-transmission/

You can try this method. I haven't tried it myself

[Unspec]

Originally Posted by chipguy

https://bmwtechnician.com/2018/07/12...-transmission/

You can try this method. I haven't tried it myself

Hm, interesting. Will look into.

[535_BiTurbo]

Originally Posted by chipguy

https://bmwtechnician.com/2018/07/12...-transmission/

You can try this method. I haven't tried it myself

where is the overfill vent??