Transmission Failure? NO oil pressure.

[DaddyDog]

The car gods frowned on me yesterday - I was running errand in my 1995 740i automatic. Stopped in front of a speed bump, put car in Park to wait to proceed and when I shifted into drive there was a dull thump and felt like a mis-shift and then it went into gear. A few miles down the road as I was pulling away from a stop it again felt like it shifted into neutral and stayed there. Engine was running smooth before and after. Had it towed to my mechanic and when they checked it this morning it was running rough and they checked oil pressure in engine and it was 0. Don't want to run until they can determine cause of no oil pressure and can't diagnose transmission without engine operating! Any clues or experience as to how to proceed appreciated.

[DaddyDog]

Just heard back from my service manager - hex nut on oil pump shaft sheared off. Install new oil pump and hope the synthetic oil did its magic while the pump was not working.

[ROYinGA]

several years ago. The nut fell in my mechanics hand while he was checking the pump for loose bolts. I saw it happen. A near miss. At that time there were only 2 750 oil pumps in the US warehouses. Must have been some kind of bad heat treatment problem with the shaft. Did your shaft fail or did the nut just come off?

[DaddyDog]

Mechanic found the nut in the pan and when he tried to put it back the end of the bolt broke off in his hand.
Does anyone know if the transmission fail safe will have to be reset after new oil pump is installed?

[ROYinGA]

[martin]

i have a 2000 740i that always has a rattle when i start the engine and just today it turned into a knock and the service engine soon light came on ! i opened oil cap it seemed dry up top ! i was wondering has this happened to anyone and if someone could provide assitance

thank you