Auto tranny problems (1st-to-2nd= LIMP) - does it really needs rebuilt? HELP PLS!

[E34_buch]

I've had my 1991 E34 for 5 years now. It's a great car and the automatic transmission is so handy, but caused me so much hassle.
Reason why I got a manual 2001 E39 520d, which let me tell you is WAY lower as power and felling than the reliable M50.

However, the auto tranny on my E34 caused me problems from the first month after I bought it. I had come to the point where I am forced to sell the car because of it. A rebuilt is very expensive in my area (I live in Europe), mechanics are few and not reliable for this type of job. A good used gearbox is impossible to be found.


I have searched every thread on this forum related to "automatic" problems. No one seems to have exactly the same problem with me, although the service said is quite common.

The car is 520iA 24 V - M50 engine. Gearbox type is A5S 310Z-KN (produced between 90-92).

Eversince I bought the car, the auto reved up between 1st and 2nd gear then hit the LIMP mode with a shock. If I turn it OFF and leave it a few seconds the car will work just fine, perfectly and smooth without any kind of trouble, for the whole day.

This only happens when the car sits for a few hours. In the beginning it happened during the summer, when the temperature was hot. Now it happens almost each morning, even in the winter. Sometimes it needs to be "reset" a couple of times.

Went to the service many times, they said it needs a rebuilt as the disks are messed up, but without too much attention given to the car.

It happens only when the car stood still for a few hours, therefore I suspect it might be something else: dirty switch, sensor, etc. When it succeded to "pass" this problem, it works perfect!

All tranny maintenance in the last 5 years resumed to changing the filters and oil. Service didn't recommend anything else during these years.

Any tips would be highly appreciated. It's probably the last chance to keep this car.

[granit_silber]

I've had my 1991 E34 for 5 years now. It's a great car and the automatic transmission is so handy, but caused me so much hassle.
Reason why I got a manual 2001 E39 520d, which let me tell you is WAY lower as power and felling than the reliable M50.

However, the auto tranny on my E34 caused me problems from the first month after I bought it. I had come to the point where I am forced to sell the car because of it. A rebuilt is very expensive in my area (I live in Europe), mechanics are few and not reliable for this type of job. A good used gearbox is impossible to be found.


I have searched every thread on this forum related to "automatic" problems. No one seems to have exactly the same problem with me, although the service said is quite common.

The car is 520iA 24 V - M50 engine. Gearbox type is A5S 310Z-KN (produced between 90-92).

Eversince I bought the car, the auto reved up between 1st and 2nd gear then hit the LIMP mode with a shock. If I turn it OFF and leave it a few seconds the car will work just fine, perfectly and smooth without any kind of trouble, for the whole day.

This only happens when the car sits for a few hours. In the beginning it happened during the summer, when the temperature was hot. Now it happens almost each morning, even in the winter. Sometimes it needs to be "reset" a couple of times.

Went to the service many times, they said it needs a rebuilt as the disks are messed up, but without too much attention given to the car.

It happens only when the car stood still for a few hours, therefore I suspect it might be something else: dirty switch, sensor, etc. When it succeded to "pass" this problem, it works perfect!

All tranny maintenance in the last 5 years resumed to changing the filters and oil. Service didn't recommend anything else during these years.

Any tips would be highly appreciated. It's probably the last chance to keep this car.

i don't know it this will be much help, but have you cleaned the gear selector switch in the center consol?
-ashley

[E34_buch]

i don't know it this will be much help, but have you cleaned the gear selector switch in the center consol?
-ashley

Almost certain the previous owner neither....
Which selector are you refering? Is it the S/E/Winter one, where you change the mode or something else?

[granit_silber]

Almost certain the previous owner neither....
Which selector are you refering? Is it the S/E/Winter one, where you change the mode or something else?

It's the whole black assembly. I'm not sure how to take it out. Do a search for it. Like I said, I don't know if it will help. But that little selector has been the cause of other funky trans problems in the past.
-ashley

[E34_buch]

It's the whole black assembly. I'm not sure how to take it out. Do a search for it. Like I said, I don't know if it will help. But that little selector has been the cause of other funky trans problems in the past.
-ashley

Thanks, I will check that next week...

Other ideas pleease?

[pyro]

Its under the shift consil. its a black box as he said and it comes out with a allen key. (not shure if thats the proper name for that tool)

[E34_buch]

Is this the only device or are there more?
I just left the car in service and they will verify it once again tomorrow morning.

[E34_buch]

Anything else to check in order to avoid the rebuilt?

[SharkmanBMW]

use the search button and scan through the old posts.... there have been many people with similar problems as yours, see what they did, cleaning switches..... the "search" results will give you many pointers.
I would start with "limp mode"