Replacing Flywheel sensors carrera 3.2

snaga61 · 01-12-2006, 10:00 AM

Has anyone replaced their flywheel sensors? How do you access them?

Thanks for any input.

RickM · RickM's Garage

Welcome to the board.
These threads should give you a great start. The search feature is your friend....

3.2 DME Speed/Ref/CHT Sensors...

3.2 ref sensor flywheel sensor questions

3.2 speed sensor question

MotoSook · 01-12-2006, 10:31 AM

They are on the drivers side of the bellhousing. With the car on jackstands you can easily remove them. Once you are in there, it'll seem pretty obvious. Pull the rubber grommet out of the sheet metal and you can take the sensor lines out of the grommet.

snaga61 · 01-12-2006, 10:41 AM

Thanks guys! I'll check it out his weekend. Figure its time to replace all those things that can contribute to an ignition problem down the road.

MotoSook · 10:59 AM

The sensors look exactly the same and they are the same technically. One is used for speed sensing and the other is for reference sensing (the pin on the flywheel...crank position). Why you diassemble mark the two connectors in the engine bay so you know which one goes on the speed sensor and which on goes on the reference sensor. That's the only tip I'd offer as the rest is pretty straight forward.

Might consider changing the head temp sensor too. Upgrading to the 2-wire sensor.

(Oh...you are aware that there is spec for the sensor to flywheel distance, right?) Keep that in mind when reading the other threads.

Good luck and have fun.

Rot 911 · 01-12-2006, 10:52 AM

Here's a picture:

ChrisBennet · ChrisBennet's Garage

Kurt,
Is it just the picture or do those sensors have a 2-4mm gap (vs .8mm spec)? I've heard the that they will run fine with a gap greater than spec and have problems with a gap that is too small - kinda counterintuitive.
-Chris

Rot 911 · 01-12-2006, 12:42 PM

Chris I really can't tell you what the gap was. With new sensors I do set them at .8mm. These were obviously old sensors.

MotoSook · 01-12-2006, 12:58 PM

I've got a BMW with Motronic engine management. (see More electron Warfare! (Motronic ignition) )

I have over 1mm gap (probably closer to 2mm) between the sensor and the reference pin, however the sensor to the ring gear distance is stock. I'm still troubleshooting my hot start, but I doubt it's related to the pin.

On the BMW the two sensors are independently mounted, unlike the 911. I am guessing that the gap to the ring gear is more critical that the gap to the reference pin. The resolution on on that sensor has to to be several times greater than the pin sensor. But then I will state again...electrons and I don't get along.