Accepted Answer

The problem is the thermostat. When driving the air across the radiator cools down the engine and at lower speeds it doesn't get as much air so the coolant stay warm enough to keep the heater working.

 

Replace the thermostat and it will fix the problem (instructions attached).

 

If you still need help just reply, if not click ACCEPT when we are done.

 

Thanks,

 

JB

 

THERMOSTAT Thermostat View Full Image REMOVAL Drain the coolant to thermostat level or below. Remove the inlet fitting and gasket. View Full Image Remove the thermostat. INSPECTION Heat the thermostat as shown in the illustration. Check that the valve operates properly. View Full Image Verify the temperature at which the valve begins to open. Valve opening temperature 80 - 84°C (176 - 183.2°F) Full opening temperature 95°C (203°C) INSTALLATION Check that the flange of the thermostat is correctly placed in the socket of the thermostat housing. Install the inlet fitting. Tightening torque Engine coolant inlet fitting bolt 17 - 20 Nm (12 - 14 ft. lbs.) Refill the coolant.

 

Expert:	brownjeff
Pos. Feedback:	100.0 %
Accepts:
Answered:	11/30/2008

ASE Certified Technician

17 years experience, ASE certified, dealership certified, Service Manager for 15 years,