Citroen XM Forum

Hello All,
I have just bought a 2.1TD manual 1992 and the heater has stopped working. I suspect an air lock but cannot see if there are any bleed screws on the cooling system. Any ideas? Cheers, William.

Hi William

Welcome to the club (if I haven't done so already) First thing to do is check the temperature of the heater hoses where they go through the bulkhead, just behind the top of the engine, if one or both are cold then you have no water flow but I think this is unlikely unless you are loosing water possibly because the head gasket is leaking, what is more likely is that the mixer flap in the heater is not moving, if its a VSX it is controlled by a motor which sometimes fail or if its an SX its cable operated.

Peter

Thanks for the advice Peter. Will check and confirm. The water level had been low and I have topped up, which made me suspicious in case of gasket problems. I also have a 2.5TD which has lots of bleed screws, which is why I wondered about the air lock issue.

The 2.1 has a very well designed cooling system, almost impossible to airlock as long as it is filled right up but a leaking head gasket can cause an airlock in the heater, or rather a 'gas lock' but if the gasket is that bad you will be loosing large quantities of water through the header tank overflow. My white estate has a leaky h/g but I have driven it 5,000 miles or so with no problem by loosening the filler cap which allows the pressure to escape, if the gasket is really bad it will blow the water out under these conditions.

Peter

Hi William, if you look at the two hoses going into the bulkhead for the cabin heater you'll find a bleed cap on one of these hoses. There's also another one a little harder to find... stand in front of your car, look at the rear left of the cam cover and then peer downwards - there's a pipe that comes from the thermostat housing at the rear of the engine that terminates in another bleed cap.

Good luck. Hope it isn't the head gasket (been there, done that)

Colin.P

I had forgotten about that