Xantia V6 Cutting out and Starting Problems

Unread post by **DHallworth** » 20 Jun 2010, 22:50

Our Xantia V6 seems to be giving problems at the moment.

It started to be hesitant and snatching when moving off until I changed the fuel filter and that seemed to cure that, guess it was just being starved of Petrol.

Now it seems to be cutting out, the revs fluctuate to suit it's temperament and when it's remotely warm, even after running for 2 minutes it seems to refuse to start.

Tonight I just managed to coax it into starting, and when it did start it seemed like there was a plume of grey smoke from it. I ran the Lexia on it and it told me there was a temperature sensor giving a bad reading.

Only problem is it didn't tell me which one it was likely to be. Instinct tells me it's likely to be the brown sensor, is this the one that talks to the Bitron box?

Thanks in advance guys.

David.

Unread post by **xantia_v6** » 20 Jun 2010, 23:40

It won't be the brown (bitron) sensor, as that only affects the cooling fans and A/C. The engine ECU uses the green sensor (I think). A faulty temperature sensor can cause very poor running.

I don't think that either of them are easy to get at. I think that the Lexia actually tells you the temperature measured by the green sensor, so you should be able to get a "second opinion".

Was the sensor fault current, or just a stored fault?

Unread post by **DHallworth** » 21 Jun 2010, 00:44

xantia_v6 wrote:It won't be the brown (bitron) sensor, as that only affects the cooling fans and A/C. The engine ECU uses the green sensor (I think). A faulty temperature sensor can cause very poor running.

I don't think that either of them are easy to get at. I think that the Lexia actually tells you the temperature measured by the green sensor, so you should be able to get a "second opinion".

Was the sensor fault current, or just a stored fault?

From memory without going and checking again, I think the temperature sensor was reading a constant 30 degrees.

David.

Unread post by **CitroJim** » 21 Jun 2010, 06:04

The Green (ECU) sensor is easy enough to get to. It's the brown Bitron that's a pain..

This pic shows it, just below the lower green arrow... The original picture was done to show the bleed valve locations.

Don't forget there is also a temperature sensor on the airbox by the idle air hose...

30 degrees F or C?

Unread post by **xantia_v6** » 21 Jun 2010, 07:07

30 degrees may be a default limp-home value if the ECU has detected a failed sensor, if so, it should start and run OK when cold, but will be rather rich after it has warmed up.

The problem could of course be a broken/corroded wire to the sensor, rather than the sensor itself.

Unread post by **DHallworth** » 21 Jun 2010, 09:06

Is there any way of testing the sensor?

Would be handy if I were able to tEst it's resistance to find out if it's knackered or not.

Thanks guys

David.

Unread post by **CitroJim** » 21 Jun 2010, 09:14

I bcan give you a ball-park resistance reading later today David.

It'll be whatever themperature my workshop was at the time of reading.

Unread post by **DHallworth** » 21 Jun 2010, 10:02

Thanks Jim,

If I take the sensor out and change the temperature I should also be able to see it changing soil do that this evening too.

David.

Unread post by **citroenxm** » 21 Jun 2010, 12:50

hmm I wonder if this is whats causing a missfire when cold on my V6... once warmed through shes perfect through the rev range, so I cant see it being coil packs, also has new plugs...

Paul

Unread post by **CitroJim** » 21 Jun 2010, 14:22

citroenxm wrote:I cant see it being coil packs

No, coils will play up when hot. very rarely do theu fail when cold..

Unread post by **citroenxm** » 21 Jun 2010, 15:06

No, which sensor then Jim???

Time to play the guess game, OR have you a set of known good ones I can plonk in when shes next on the repair list..??

Paul

Unread post by **CitroJim** » 21 Jun 2010, 16:58

citroenxm wrote:No, which sensor then Jim???

Lexia

You have one haven't you Paul?

David, green sensor reads 2.9K at 21 Degrees...

Unread post by **DHallworth** » 21 Jun 2010, 17:07

CitroJim wrote:
citroenxm wrote:No, which sensor then Jim???
Lexia You have one haven't you Paul?

David, green sensor reads 2.9K at 21 Degrees...

Brilliant, Thanks Jim, I'll check this one tonight.

A new one from Cit is £31.

I'll warm it up and cool it down and see if I can get a different reading from it. If I can then I'm guessing it's another wiring fault like the heater on this blasted HDi.

David.

MikeT · Unread post by **MikeT** » 21 Jun 2010, 18:04

DHallworth wrote:
A new one from Cit is £31.

I just replaced mine on the 1.9TD but it was about 2/3 that price. Do you know the part number? It's possible they're the very same part.

Unread post by **DHallworth** » 21 Jun 2010, 18:09

MikeT wrote: I just replaced mine on the 1.9TD but it was about 2/3 that price. Do you know the part number? It's possible they're the very same part.

I do indeed...

Part number given to me by Citroen Glasgow was 133891.

I should also say it was £31 + VAT so will be about £38.

Are they the same between Petrols & Diesels?

David.