1994 E36 M3 - RPM Sensor Connector

[dylan0451]

Doh!

went to cross a ford this morning, water came up to, and just over the wheel rims. as i continued it threatened to lap over the sill, so i aborted the fording attempt, reversed and found another way around.

after that, as i was driving at a steady speed the rev counter was bouncing back and fourth all over the place, so i assume the connector on the engine (coil?) got a dipping.

where is the connector located? should it just be a case of drying out, cleaning up the contacts and a little application of silicon grease round the seal?

[Vixpy1]

The dash gets its reading from the ECU. If its just the rev counter and the engine is running fine I would suggest you have water near the ecu or its wiring.

[dylan0451]

ok, i assume though that the ecu isn't mounted in the wheel arch or somewhere daft? there still has to be some electro/mechanical sensor somewhere, that sends a signal to the ECU

could it be the crank sensor if BMW's don't use the coil?

[Vixpy1]

dylan0451 said:

ok, i assume though that the ecu isn't mounted in the wheel arch or somewhere daft? there still has to be some electro/mechanical sensor somewhere, that sends a signal to the ECU

could it be the crank sensor if BMW's don't use the coil?

crank or cam sensor wiring yes, but i would expect the engine to misbehaving if it was.

ECU is in the engine bay by the bulkhead

[dylan0451]

hmm... well i'll see if it's playing ball tonight when i leave work.

my only thought could be that there's been water ingress via the engine/bellhousing or clutch dust exit point on the bellhousing, leaving the ring gear to chuck water everywhere, although as you've said, i would have expected the car to at least have run lumpy if it was getting an odd signal from the crank sensor, which it hasn't at all.

cheers for the advice, might have to pop down sometime and get the old girl on the rollers!