E36 320 after the rain

[grave77]

I have a friend who drove his car into a puddle due to floods, after that the engine starts with a very low RPM and we had to idj. the throttle screw to gain the normal RPM, still when the car is cold and you hookup the gear it switches off, I suspected the O2 sensor. recently the RPM is reaching 1500RPM while idle and then back to normal, when the car is warm and driven for a long time, the car starts acting more hesitant.

I know there would be many factors here, but may you help us were to start?

Thanks

[bmwe36]

is it automatic transmission ...if so some times water gets in to the wiring harness to the transmission changing the preformance of the transmission making the engine proform poorly ....hasitation....late shifting ...i dont now if it related to ur case but from my experiance that what i found out on 320is auto.......
cheers