My heater just started doing this.
It does not seem to be putting out nearly as much heat and when I come to a stop, say at a traffic light or something, it starts blowing cold air.
Starts blowing hot again as soon as a start moving.
Engine does not appear to be running too hot or too cold.

What could it be?



1991 4Runner V6(3VZE) 5-Speed 4X4 SR5
349,000 Miles and STILL Running Strong!!!