Quote:
Originally Posted by Number 6
The heater in the car (75 Diesel), has all of a sudden started to play silly luggers,, From cold with the temp set at 20 both sides the hot air starts to increase as the engine temp rises. All good, but after 20/30 miles at a sustained speed cold air starts to blow thru the vents, turn the temp up and you get warm air. There are no sign of over heating. The pipes to the heater matrix are both hot when the cold air starts to come thru the vents 
Any one have any suggestions?? |
switch off the auto mode, and switch to recirc (there is a combination of settings similar to this, but I can never recall it).
Mine does this, but it is limited to the upper drivers side air vents. Feet, and passenger sides remain warm. I have read this is a normal safety function to keep the driver alert.
If all of the vents turn to cold, then I would suggest an issue with the vent mixer flaps, or an issue with the air sampling inlet vent.