ZX/XUD Revcounter

[Chlorate]

The revcounter/tachometer in my ZX doesn't work.
I'm told this is a fairly common problem in old Citroen diesels and can be relatively easy to fix.

-Where is the revcounter sensor?
-Is it easy to remove?
-How much would a new sensor cost, or can the old one be repaired?

My guess is that it's attached to the flywheel somewhere, but I can't find it for the life of me.

Any help on this would be greatly appreciated, photos of it even more so

[citronut]

its on the rear of the engine block gear box end and just below the bottom edge of the head, and above the speedo drive,

firstly check clean the terminals in the brown (i think it is ) plug conector,

you will find this plug by following the wire from the sensor, sometimes its just disconected,

and no the sensor is not repairable GSF sell them i think this might be the one N92535,

but ask GSF when/if ordering just in case im wrong

regards malcolm

[Chlorate]

Cheers Malcolm.
That's in an awkward place and a half..
I found a green plug with a wire leading off to the general area you're talking about, but I can't get my fingers around there, let alone tools to see what it is.
Have any more tips?

[Stunned Monkey]

yes it would've been sensible to have a crack at it when the head was off......

[Xantidote]

The rev counter on my TD Xantia was playing up earlier this year, intermittently dropping to zero. Sometimes reving the engine/engine movement revived it, otherwise it would start working again of it's own accord. Got progressively worse.

Xantia has 3 way plug-socket on top of gearbox, with a single black 3-4mm diameter cable going to back of block as Malcom describes. I disconnected and remade this connector several times. I also removed the sensor but nothing to see, so refitted it, and at same time, slightly changed the angle of the cable where it enters the sensor's plastic body, in case wire was fractured internally.

Any which way, rev counter now behaving - I think most likely it was the plug-socket connectors. I'd try the connector first. Hope this helps.

Martin

[citroenxm]

Xantidote

Two things there, in your post..
Firstly, the sensor end can get covered in crap, this will cause the "dancing" rev counter, removing the sensor, prehaps moving crap, then pushing it back in, you could very well have push it back in firther then it was before, meaning it being closer to the flywheel enough for it to sense the tip .. Ive done this myself, by simply pushing it in a bit further can bring the rev counter back to life, but ideally it needs removing, one 10mm nut, to slacken the plastic Clamp, clean the end off, and pushing back in..

This is easyer done from under the car, put her up on RAMPS then what I do, is start the engine, and lightly tap the sensor in untill the rev counter starts working, then tighten the 10mm nut up..

The sensor CAN be QUITE tight in the clamp too! Ive snapped a couple trying to remove them before now.

Regards
Paul

[Xantidote]

Paul, you are quite right, and I did rather simplify what I said as regards the sensor, as I felt the plug-socket the likely culprit. When I removed the sensor (yes - access from underneath), it was a bit oiley, so cleaned with rag. Maybe in the removal & cleaning, I disturbed some dirt.

After tightening the clamp bolt, I did ponder it's distance off the flywheel, and having refitted sensor & tightened the bolt, I measured the sensor-flywheel gap with feeler gauge as 12 thou. No information/data in BoL, and I didn't think to measure it before I took it out, but decided that this was a reasonable clearance, bearing in mind the permissible crankshaft end-float.

Most of the time, the rev counter is irrelevant, but, bit like the clock in the fascia, as soon as it stops working, you miss it! So I'm pleased rev counter's working again. Next time, I'll try one remedy at a time - then I'll really know what the problem was.

Thanks very much for your comments

Martin