Cab Heater only blows warm when vehicle moving????

[lea.bridge]

Cab Heater only blows warm when vehicle moving????

Can anybody give me any info on this problem before I put the car in the garage (doh!). I have a 2000 series 2 disco TDI Auto with Air con. When the vehicle is stationary the air it blows out is cold no matter how high you turn the temp up, once the vehicle starts moving the air blowing out starts to warm up, the faster it goes the warmer it gets or so it seems, so I try not to get stuck in traffic in this weather!

Any advice would be greatly appreciated.

All the best to you all for the new year.

Cheers

Lea

[Snagger]

I'd start by replacing the thermostat.

[browng5]

Sounds like the symtoms I had on my 99MY DII. I changed the thermostat but it turned out to be the early signs of head gasket failure. The heater was cold at tick over but when I increased the revs to around 1500rpm I would start to get heat through the heater.
On mine, after a long run the top radiator hose was pressurised and the water level in the expansion tank was out of sight. Leaving it to cool for a bit and then slowly opening the expansion tank cap the water level would return but always to a lower level.
If you search this forum there are plenty of posts covering this.

Let us know how you get on.

Graeme.

[lea.bridge]

Thanks for that.
I have ordered a thermostat today and hopefully change it tomorrow
(that looks intresting in itself) but i will let you know how i get on
Cheers

Lea

[browng5]

Remember and use the proper antifreeze. It should be pink/red in colour and contain no Methanol.

Good luck, it is quite fiddly and you need a thin 36mm spanner for the viscous fan.

Graeme.

[lea.bridge]

Thanks for your help Graeme,
I checked the system for an air lock today and found that there was no water coming out of the bleed screw even though there was water in the header tank, so I raised the header tank about five inch and managed to get about 1ltr of water into it and then the water started to come out of the blead screw.
Tried the heater and it was working ok.
The only thing that worry's me now is where the 1ltr of water went (head gasket springs to mind)

May be time for a trade in.

Cheers

Lea