Discussion Starter · #1 ·
Lately my heater will blow hot air when it gets to operating temperatures then it will go cool for a bit then back to hot. Coolant level is to the top of radiator and there is no drop in coolant temps when heater starts to blow cool air. I don't have auto climate control just the manual temp dial. Could I be having a vacuum line issue that is causing the blend door to open and close causing the fluctuating heating temps? Any idea on what I should look for to fix this would be great.