Citroen XM Forum

Nice one Rob. Great chatting to you earlier on too.

Hi Rob,

Your car looks great, a deserved rosette win for you.

Great to say hello yesterday Rob and great on the rosette. Richly deserved

Bit of an odd problem that I would like some advice on...

Two weeks ago, when driving in heavy traffic on Newcastle's Western Bypass, the engine temperature started to creep up beyond its usual operating temp of 60-70 degrees towards 80 and the temperature in the cabin also rose; however when adjusting the digital heater controls to a lower setting no change resulted, the car continued to blow hot air. On regaining useful forward momentum (I like that phrase) the engine temperature returned to normal but the heater continued to blow hot.

Subsequently the heating/cooling system seemed to work properly until today when the reverse effect occurred. Today the engine temperature remained static at just over 60 throughout two one hour journeys, but the heater refused to blow anything other than cold air into the cabin.

For reference, the car is a 1992 2.1 SED Auto with digital climate control. I am intending to get the air con system serviced for the summer but this current issue seems to be something other than just air con cooling related. Any thoughts? The Book of Lies hasn't offered me anything, but I have every confidence in the knowledgeable ones

Rob

Hi Rob, mine is the same car...model ect, and I was told by the 'specialist' I bought it off, it should sit at just under 90. Sort of 85-90, should be normal. The only time it has risen above 90 was due to binding brakes. It would climb a bit an then fall as and when the brakes were binding. My issue was the Doseur valve linkage seizing. Might be worth checking it.

I wonder if you have a different thermostat on yours for it to be at 60 to 70 as your normal temp.

If the engine doesn't get upto proper temperature, the interior control doesn't work properly as there isn't enough differential between the cabin and engine temperatures.

yep -and it should be just under 90 - some thermostats sit at just on or over 90 but a regular XM (petrol or diesel) should sit at about 90C.
thermostat need changing?

So a replacement thermostat is looking like a good starting point then?

Rob

The temp reading should be at 80c for a diesel i have had mine changed twice thinking there was something wrong as it would only get to 90c on climing hills or stuck in a traffic jam, the stat temp is stamped on the bulb end of the stat, so went to citroen and looked into it and the 2.1 auto cars have a 80c stat and the manuals a 85c stat so i got a manual car one, now it sits at 85-90c and i also cleaned out the cabin temp sensor in the roof (it was blocked up with fluff) lubed the bearing (it squeeked) and now it maintains a nice steady temp in the cabin.

Regards,
Norman

I am assuming the cabin sensor you mentioned is located between the courtesy light. I have had a look there this afternoon and it is all clean, but there doesn't seem to be any moving parts...

Gave me the chance to fit a new bulb though!

Rob