Ford Fiesta (X reg) heater

Temperature light??? thats a new one you don't have a temperature gauge on your fiasco? run the engine for a couple of minutes from cold then check the top radiator hose it should be more or less air temperature if its getting warm suspect the thermostat is sticking Derek

These have a water valve on the bulkhead that is a very common failure bit. I have never had to change one personally, but I understand it is quite easy.

mrcheerful

It's an easy thing to change, and is located in the centre off the bulkhead. Just a case off disconnecting the four hoses, unplugging and sliding out the old valve, sliding in the new valve and reconnecting everything. When changing the valve, it's worthwhile flushing out the heater matrix, as they tend to collect any rubbish in the cooling system. Just run a garden hose through the pipes in both directions until the water runs clear.

It's most likely the valve, but it's easy to check. Disconnect the electrical connector, connect a test lamp across the connector, turn the heater control to the centre position, and with the engine idling, the light should flash. If it doesn't flash, then the fault lies in the control somewhere.

The dial operates like a thermostat on both the Fiesta and the Ka and operates a water valve in the engine compartment near the bulkhead. The dial pulses the water valve on and off to give you varying air temperatures.

The water valve is a known common failure. Check this first.

Tim..

Have you checked to see if there's actually any water in the engine? Usually this is a sign there isn't.

OK, I'm a moron.

When I got back and looked last night it appeared there was. The top radiator hose was hot (but it is directly above the exhaust manifold) and the expansion tank was pink up to the line...

However now it's cold and I've taken the cap off it appears the expansion bottle was just stained pink and there is indeed no coolant in it. Joy.

Ah. Next question is "Where has it gone?" Check the oil too as a low oil level can cause an engine to use water.

Heh, checked the oil (and all other fluids) when I discovered the coolant was low. It's OK (no signs of water in it, either).

The oil seems to be fine (no signs of water in it either).

I've discovered the coolant is leaking from the inlet manifold. For some reason that I can't quite work out, the coolant passes through the inlet manifold on its way to the heater matrix.

I'm going to attempt to replace the gasket over the weekend, with some help. Hopefully the (very) small rubbery bit that is sticking out of the inlet manifold/cylinder head join _is_ a bit of the gasket which has failed, and replacing it will cure the problem...

Thanks for the replies, everyone.

Its to help cool the air passing through the inlet manifold when its hot to keep the density up. When its very cold, it keeps the air a bit warmer to prevent the fuel vapour icing up.

David Taylor wrote on Fri, 6 May 2005 16:32:01 +0000 (UTC):

It was a bit of the gasket, and thankfully replacing the gasket has stopped the leaking. Yay.