Citroen XM Forum

Ah, cheers for the info Graeme, i think the Temp sensor Dieselman will be meaning is the water Temp sensor, pretty sure this is the one above the oil filter ?, pretty sure problems would be a lot worse if it was a fuel pressure issue.

May try and get a new Temp sensor tomorrow and bung it in, only a tenner or so, worth a try.

Right, did a bit more research, recon the sensor above the oil filter is the oil pressure light, the water temperature sensors are on the housing on the right of the head under the coil pack, there is a bown, blue and looks like there is a green one further down, a'm i right in thinking the green one feeds the ECU ?

Yes, the blue one I think is instrument temp gauge and the blue one fan control, I think, don't hold me to it though, there is an air temp sensor on the throttle body which I THINK is a yellow plug and then the map sensor is in the ECU with a hose running from the throttle body, its only these three sensors and lambda that are associated with the mixture.

The green plug above the oil filter is probably the knock sensor, if its missing under load in a high gear it would suggest to me a spark issue, unlikely to be the coil pack when cold but it could be the ign control module, they do weird things there was a recall on this age ECU for stalling on a trailing throttle when cold which can be uploaded by a friendly Lexia owner but I would say this has been done.

D

Cheers for the info Dean

Dean wrote: there was a recall on this age ECU for stalling on a trailing throttle when cold which can be uploaded by a friendly Lexia owner but I would say this has been done.

D

Ah, the ECU in this car has been modified (chipped), there was a theory (in Graeme's thread) that this may have deleted the Recall.

Will be trying another ECU soon, but will change the ECU temp sensor for all it costs, look's like the coil pack and poss the intercooler hose will need to come off to get access to it.

Had the car out earlier and it ran perfect.

Funnily enough was out to order a new green temp sensor (motor factor couldn't get one anyway)

Poor running definitely seems dependant on ambient temperature.

Also had a good look underneath earlier (while trying to see if the temp sensor is easier to get to from underneath), it's absolutely solid , just a few areas i need to scrape and attack with Kurust and underseal, will get that done soon.

What's everyones thoughts on yellow tinted lights ?, not the headlights just the bumper indicator/fog units. Was going to get the stick on film from E-bay.

Used it on the fog and main beams on my old 750iL and liked it

Yellow film really reduces the light output. I recently saw a lorry with yellow filmed lights and was surprised the driver did the mod.

XM low beams are yellow tinted anyway by now, courtesy of aging plastic lenses lol that's another of the more minor issues to address on our silver estate in between bouts of rust warfare. IMO it might look nice but if you're doing any night driving avoid it.

having said that, it would look good and not affect night vision on just the indicator/fog lenses.

Plenty of gold and yellow-tinted H1 lamps on the web...

Re your ECU and running problem, It could be that the ECU remapping was not optimal for low temperatures, and is giving a lean mixture.
You could try adding a 1k Ohm resistor in series with the coolant temperature sensor, which will make the ECU think that the engine is colder and deliver a bit more fuel.

White Exec wrote:Plenty of gold and yellow-tinted H1 lamps on the web...

Going to go for yellow tinted H1's in the main beams (blue tinted ones in there at the moment) and yellow film on the bumper light units.

xantia_v6 wrote:Re your ECU and running problem, It could be that the ECU remapping was not optimal for low temperatures, and is giving a lean mixture.
You could try adding a 1k Ohm resistor in series with the coolant temperature sensor, which will make the ECU think that the engine is colder and deliver a bit more fuel.

Yep, agree that's a possibility, desperate to try a standard ECU though before messing about with resistors, hopefully soon.

Pulled out the spare wheel carrier earlier, just a bit crusty on one side so will weld in some fresh steel, give it a good scrub, de-rust and repaint.



Underside is solid but some surface rust on the rear subframe needing treated, also some surface rust near the frame mounts, will clean it all and give it a blast of Dinitrol.



Suspension problems have reared their head again , noticed the tell tale Hydractive light Graeme fitted was staying on all the time, suspension felt stiff, had a look through his thread for some pointers, unplugged the throttle sensor, suspension is soft all the time now and light is out, can live with it like this for now but something else to sort.