Rev counter sensor

Oscar · Post by **Oscar** » Fri Aug 18, 2006 10:12 am

Hello

Does anyone know where this is located, where to buy a new one, and how to replace it please?

thanks

Oscar

jeremy · Post by **jeremy** » Fri Aug 18, 2006 12:24 pm

Its on the back of the flywheel. Get underneath, scrape the mud out of your eye and you will see a cylindrical device (1/2 in diameter) lying parallel with the engine. Its held with a pinch bolt - loosen and pull out, and disconnect the wire from the connector in the under battery area.

New one is <£20 from Citroen I think. Others MAY use something similar like ZX but may have a different plug or something. Push new one in and tighten. Plastic feet will grind off leaving the correct clearance when the engine is running.

Worth checking carefully as the cable may have broken and it may be possible to repair by careful soldering. Bit like an ABS sensor I thinkl - so should meter. Wire flexes at unit and may break there but there may be stubs to solder to and if its doen carefully you may be able to re-use it and clip the cable to the body as support or something. May even be able to encapsulate in polyester resin or even epoxy.

Oscar · Post by **Oscar** » Fri Aug 18, 2006 12:43 pm

As it happens, I've just bought a soldering iron and some 60/40 solder.

Thanks Jeremy, I'll have a good look and report back.

Regards

Oscar

AndersDK · Post by **AndersDK** » Fri Aug 18, 2006 3:06 pm

Anxious to read about your experiences on this Oscar

My 17TD will be next to get this surgery then

Kitch · Post by **Kitch** » Fri Aug 18, 2006 6:16 pm

Do the N/A diesels use this system too? Wondered how tricky it would be to fit one to a car without rev counter as std. Clocks are cheap looking and boring!

AndersDK · Post by **AndersDK** » Fri Aug 18, 2006 6:20 pm

Yes - n/a rev counter installation is exactly the same.

Brian · Post by **Brian** » Fri Aug 18, 2006 8:58 pm

Hi Folks,

The sendor on my TZD went low ohms and was not repairable.

So I popped in the TDC sendor which very seldom gets used, and guess what!!! It worked..

The end plugs are similar, so it is a direct replacement...

Jaba · Post by **Jaba** » Fri Aug 18, 2006 9:55 pm

Dont understand that Brian. The TZD does not have a TDC sensor. The petrol injection engines with an ECU have one in the top of the gearbox but this is a different size and will not fit the clamp which is around 10mm.

The non ECU petrol engines do have a similar sensor, used for diagnostics. I think they are different to the diesel rev counter variety tho. They meter out differently and I could not get one to work when I had a failing rev counter sensor.

However my rev counter did spring into life when I refitted the sensor closer in to the flywheel.

AndersDK · Post by **AndersDK** » Sat Aug 19, 2006 9:21 am

The diagnostic sensor will work just as well - as will a TDC sensor. Its just a matter of getting the connections right.
But of course any sensor used must be fitted/moved to the same place as the rev counter sensor.

The opposite is true as well ...

Because there are no "secret" or elaborate functions built into these sensors. They are just plain wire wounded coils - nothing else.

tom · Post by **tom** » Sat Aug 19, 2006 10:21 am

Data on the DIY section of the homepage.
It will be the sensor that is duff; It should read 270 Ohms, a job for that nice new multimeter Oscar. GSF sell 'em for around a tenner and there are two likely sites, one is tucked away behind the pump, above the gearbox, and the other is at the rear lower part of the bellhousing and a little easier to change out. Slacken the pinch bolt and pull. When reinstalling, push it in until it touches the flywheel then just pull it back about half a millimetre before tightening. I've seen many a wrecked one as a result of making contact with the flywheel.

Oscar · Post by **Oscar** » Sat Aug 19, 2006 1:25 pm

Thanks guys.

I shall indulge my self this weekend, and get under the car on Monday, while the rest of the world is at work.

O