Frequent crankshaft sensor failure?

[gavtheoldskater]

Model is a 2.0l hdi, 2001, multispace desire.

I’m now on my third crankshaft sensor in under 2 years, the last, a genuine Citroen part, I installed last July.

I can’t believe I’m just unlucky with parts failing, though I have had two Bosch parts not work from new, so before I just give up and sell the car would anyone have any thoughts on what might be causing the sensors to fail with such frequency?

Needless to say if anyone wants to know how to install a sensor in this model i’m definitely the chap to ask! : )

[Gadgetman]

If it's anything like my 1.4i, the sensor's stuck at the end of the engine, next to the flywheel.
There's a cutout in the bell-housing for it, but it's actually bolted to the engine body.
These sensors are pretty simple coils. No physical contact with anything, really.

One failing is strange enough, really, but two?

[Gravity]

Sounds like a high resistance in the circuitry somewhere - bad plug/socket contact, or pinched wire along the loom.

Presumably the car faltered or died, or was hard to start, when the engine had warmed up - but started and ran normally from cold?

Gravity

[gavtheoldskater]

Sounds like a high resistance in the circuitry somewhere - bad plug/socket contact, or pinched wire along the loom.

Presumably the car faltered or died, or was hard to start, when the engine had warmed up - but started and ran normally from cold?

Gravity

It literally will not start. It’ll be fine, then I’ll jump in it and it will just turn over. No warning or prior signs.

I’m beginning to think electrical, possibly something to do with damp, I think I’m going to have to have a good look at the wiring and try to follow them as best I can.

Out of interest does anyone know what ohm value I should get off the sensor and if this reading can indicate that the sensor has failed or no?

[Gravity]

One problem with cps units is that they often fail once they have reached operating temperature, causing the engine to falter, or not start later in the day. When the engine is cold, they work again, due to the coil inside breaking down with heat but managing to work when cold. Hence my earlier question.

This means that if you check them with a multimeter off the car you might get a circuit, but if you were able to check them hot you might find they've gone open circuit. Easiest way is to swap the cps for a known good one. If all is well you have your answer. They are generally very reliable units, which is why I suggested that, having gone through three of them, your fault could be elsewhere.

Gravity