Questions and Answers
BMW 528i Loses All Gears
Q. Hello Mr. Ciulla, I have 1981 BMW 528i, 150,000 miles, automatic transmission, 6cylinder. The transmission problem is as follows: I can start the car and drive it for about ten minutes before I hear a faint clicking noise from the gearbox followed by the loss of all gears. Car revs as if in neutral and no sound of any shifting is heard.
When I put the car in park and turn off the engine and re-start the car I get all of the gears back for a few minutes before the clicking starts up and the gears are gone again. I can repeat this scenario dependably.
After starting the car recently and having the above result I inspected under the car and discovered that there was a steady drip of fuel from what I believe is the fuel pump (?) located near the back right wheel, in front of the gas tank. A tube connects this structure to the gas tank and the drip is coming from the junction of the tube and the "pump".
It looks as though the fuel has been dripping on a different tube or wire below that connects to the back right wheel assembly. The casing is eroded and there might be damage to this tube/wire/cable. Do you know what the tube/wire/cable connected to the wheel assembly is and could it's damage be behind the transmission problem?
Can a bad fuel pump or a problem with the fuel delivery system cause the transmission to behave the way I described above?
I really love this car... she's got an excellent engine and a near mint body and interior so I would really love to save her.
Thanks so much for your help,
EricA. Well, the first thing you have to do is repair the fuel leak. The fuel system is under high pressure and it doesn't take much to set it off. I had a 1983 528e towed to the shop with a high pressure fuel leak that ignited. The car used to be white. And after $18,000.00 worth of engine, harnesses and body work, it was white again.
Unfortunately the nine month old girl in the baby seat did not survive.
The main fuel pump is located in that area, right next to the fuel filter.
It is extremely doubtful the fuel pump is the cause of this problem. And from your description it sounds like wiring or parking brake cable. If it is the parking brake cable or brake pad warning wiring, then there is no connection between that and the transmission problem.
What it sounds like is happening is the Transmission Control Module (TCM) is disabling the transmission due to either a fault detected in the transmission or the TCM itself is bad. The fact that it does shift normally up to that point would seem to indicate the problem is not inside the transmission itself.
IAt this point I would suggest letting your BMW Dealer scan the system and they should be able to find the problem fairly quickly.
