Transmission help

[ReevesPJ99]

Hey guys, need some help diagnosing a transmission. Had the car for about a month (02 325Ci). Knew it had a little lag only on occasion with takeoff speed but shifted pretty good on a regular basis and never had any problems once up to speed. Had planned to drop the pan and change fluid as well as add a trans-X additive to try and clear things up, but other issues have prevented me from doing so to this point. Long story short, I finally get all the other issues resolved and was driving it to my permanent residence about an hour away where i was literally first thing going to address the transmission and the transmission just went haywire out of nowhere. Had been driving it lightly around before just to ensure it was in good working order before i tried to drive it an hour and some change and everything was perfect and smooth. Now it was throwing the transmission warning light and not wanting to shift. Turned around to bring it back to park and smelled burning transmission fluid. Parked it immediately, went out there this morning to see if light would turn off and it’s still there. Tried to shift into drive just to move it approx 20 yards and it won’t even move. I’m by no means a transmission expert, but I’ve heard most of these things can usually be addressed and fixed with a warning light without having to replace or rebuild a transmission.

Anyone out there have experience with this type of issue? Was literally shifting fine less than 24 hours ago give or take the occasional sluggish start in stop and go type scenarios.

Any help is greatly appreciated!

[ReevesPJ99]

Went outside after the fact and noticed now that essentially all of my transmission fluid is on the pavement spread out across three parking spaces.... good news- i know why it quit working, bad news- I have to find the leak. Anybody know if there are common leaks on these, or what kind of leak could spring on this magnitude in a day?

[jclausen]

When it blows oil out of the vent it's done, replace the trans

[ReevesPJ99]

I haven’t determined where it came from. Vent leaks don’t always signal new transmission though

[MarcoZandrini]

I bet you’ve been driving the car with low transmission fluid. Be advised that BMW sourced automatic transmissions from GM of France and ZF of Germany. They are different transmissions. The GM box uses Dexron3 fluid while the ZF box uses ZF Lifeguard fluid, whatever that is.

The GM box’s fluid pan has smooth sides while the ZF box’s fluid pan is ribbed.

The transmission fluid pan needs to be warm to the touch when check the fluid level.