Overheating and no warm air

Hi, my '98 110 defender over heated yesterday and at the same time I noticed the heater was blowing cold, I have had an air block in the heating system before which did the same thing but it cleared itself. This time I checked and it had coolant in it although it did look like the header tank had been spewing some fluid out and it was a brown colour. Topped right up with water and ran until the temp gauge was half way but still no heat out of the heater but the header tank did seem to have pressure.

Any ideas on what might be the issue would be great, thanks...

Head Gasket.

My £1 bet is on the water pump

Head gasket

There is also a squeaking noise coming from the water pump and warm water is not circulating around the cooling system.

Rev the engine with the header tank cap off and see if there's any movement of the water, if the is the the pump should be ok,

Check when it's hot that the radiators hot, and check or try bleed the heater matrix of all them are good then my head is the head gasket,

No movement in the header tank and the pipes to the rad are cold when engine is up to temp. Pipe coming out the bottom of the header tank cold and water in header tank cold when gauge reads normal.

Hope it's not the head gasket only had it replaced a couple of months ago.

No movement in the tank might be the water pump

tdis dont get air locked just short of coolant ,which can be from numerous things ,a leak ,rad not cooling ,thermostat but if coolants becoming discoloured its head gasket, you should fill and check level with thermostat housing plug removed, tank level isnt necessarily level of engine

What colour will the coolant turn?

rusty

Water pump to start with!

the 300 tdi pump impeller can some times come loose on the drive shaft inside the pump housing so it wont pump water around the engine, put a new water pump on for the cheapest and easyist to start with.
Also check the small hose from the top of the stat housing to the header tank. some times they can block up which will cause cold spots in the heating system blow it through with an airline to clear any possible blockages. if its had radweld in the system that can block this pipe.

My water pump was a cheepo plastic impeller that had worn down

I had a heating problem last year on the disco 300tdi. The temp was always on the low side of normal and the heater was abysmal. Blocked return hose from stat housing to expansion tank and the water pump impellor had come loose.

New stat, new pump and a blow job on the blocked return hose sorted it out.

aspidistra said:

I had a heating problem last year on the disco 300tdi. The temp was always on the low side of normal and the heater was abysmal. Blocked return hose from stat housing to expansion tank and the water pump impellor had come loose.

New stat, new pump and a blow job on the blocked return hose sorted it out.

Click to expand...

Eh?

How did you get on with this? The brown colour (rusty) says to me Head Gasket not sat right, but may be if your water pump had corroded badly do the same? What were your findings?