poor heating in car

[petert69]

using defrost switch - all is fine
switch to face vents - fairly warm but not hot considering temp was at 29
switch to face and feet or just feet - fan cuts down and very little heat to feet eventuallly

[Don68500]

Check the heater pump used to circulate the hot water though the heater, situated under the water header tank (the tank used to top up the cooling system).
I changed the motor brushes and it works fine now.

Don

[BrianG]

There can be two causes for poor heat:

Firstly, I agree with Don - check the heater pump: the brushes in the motor wear out (it's down to hours run rather than actual mileage). You can't get new brushes from Jaguar but you can make replacements yourself with a bit of care. This winter I had exactly this problem and fixed mine up with some modified washing machine spare brushes. Takes a bit of time but better than £250+ for a new pump!

Secondly: have you changed the engine thermostat? Two winters ago mine was giving poor heat but the heater pump was working OK; then I notoced that the temperature gauge was quite not up to its usual "normal" mark. Whilst the "gauge" is rather notorious for reliably giving a true reading of real conditions (it's driven by computer), I decided to change the thermostat anyway. Bingo! loads of heat again - and better m.p.g. too!