e30 318 m40 crank angle sensor

[turbolizard 38]

What is the factory routing of the m40 crank angle sensor wiring? Where is it supposed to go, while avoiding pulleys and belts? It just does not seem long enough to avoid the front pulleys.

I found a picture of an m42 which shows the wire going up over the water pump piping, but the m40 sensor is not long enough for this.

Picture anyone? Or a suggestion for a sensible route for the wiring.

[Silver Fox 43]

goes across the front of the timing belt cover, on the line where the two halves join. There should be a plastic housing which it clips into along with the wire from the spark lead.

[turbolizard 38]

Thanks for the pointer - I now think I have been trying to fit the wrong part. I have two sensors that have different length cables (640mm and 570mm) and I didn't initially notice the difference.

My original sensor has a wire about 640mm long and will run pretty much where you said - along the red line in my picture (actually an M42 but similar sensor position). I don't have the plastic wire holder shown in the M42 photo, just have one clip to hold wire away from pulley.

The other sensor I was trying to use has a wire about 570mm long - it won't fit and is perhaps off a later motor where I think the sensor was mounted up higher.

If I could get a longer wire version, say about 750mm, then I could go up over the water pipe like the M42 and it would be right up out of the way. In its original position the wire seems very vulnerable to nicks in the insulation. Otherwise, I will try and find one with 640mm wire and fit in original position.

Does anyone know if these sensors are interchangeable with different length versions available?