Thread: Weird Trans problem

I'm copying this from a BMW forum but this guys symptoms are exactly what mine are:

Steps are:

1. Put the car in reverse and back up.
2. Stop.
3. Put the car in drive and press accelerator (normal easy start, not pushing it hard at all).

The car starts moving forward slowly and then there is a thud/thunk and (enough so I feel it quite solidly in the seat and even have a little head movement) and then the transmission seems to be more fully engaged and the car drives normally from that point. The time from pressing the accelerator until the thud/thunk is just a few seconds. The feels like it dropping an inch in the front and today I even heard the exhaust sputter like the car was about to die. Then everything went fine and I was able to drive off.

Doesn't happen all the time, current rate of incidence is pretty low, actually, but I've confirmed now that it is a recurring issue. Happed about twice a week at this rate.

I haven't had time to test conditions fully, but it seems to occur mostly after the car has been sitting for a while. I typically notice it after backing out of my garage (driveway is about two car lengths long and slopes down at maybe a 20% grade). I back up and come to a stop, shift to drive and drive away and it happens. Doesn't seem to matter if the car is warm or cold...has happened the first time I drive the car in the morning, and also in the middle of the day after I've been parked for lunch for an hour or so.



I checked my trans fluid today and it was still brightish red and did not smell burnt. There was hardly any particles in the fluid when I rubbed trans fluid soaked fingers and didn't notice much debri at all. My fluid was high though. Its high because last summer I was having a weird problem that made my car shutter while I was accelerating out of turns, I added maybe a 1/4 quart or just under that of fluid and it fixed the problem, but put my fluid over the line.

My trans temp is normal.

Any input would be great. My Major Guard warranty expires in August '09 so I'm not too worried but would like it diagnosed ASAP because I want to get down to PRJ for a tune. Thanks.

Mine is doing the samething. Let me know what it is when you find out.

Bump.

just throwing ideas here...did you check your lower engine mount, transmission mount, and dog bones?

No but I'm dropping the car off at a shop Friday night to have them give my car the run around and check everything on saturday. My dog bones are fine. I will have them check all the mounts. I'm suspecting it might be a mount because also when my car is slowing down from say 30mph, right at exactly 7mph i get this thump that feels like its coming from right under the driver side floorboard. It happens at exactly 7mph every time and only when my trans is warm at like 115 degrees plus I would say. It feels like the trans itself vibrates once. im suspecting at 7mph is right when the trans is downshifting.