ok this one has stumped me...when sitting at a red light or a stop sign or when i slow down in traffic my heat blows cool to cold air..how ever when you drive down the high way at a steady speed you'll sweat to death...i changed the thermostat and thats not it...

if someone can help me its very much apreciated cause my girlfried is pregnant and gets cold easier now and with it being winter it blows driving to work...thanks guys

Shawn

 

this happens all the time? Everytime you slow down with the heater on it becomes cold, and Everytime you're driving at a fast pace it continues to blow hot air?

 

correct everytime i drive it if i let my car warm up before i leave it will blow like warmish cool air but when i drive it at a steady 55 or fast it will sweat you to death but when i drop rpms to slow down or come to a stop it get cooler and cooler then it will be like i have the ac on both of my rad hoses get warm like there supposed to...only thing i can think of is when coming to lower rpms and to a stop the water pumps not working properly.....because if im stoped and hold the rpms between 2500 and 3k it will blow hot air

 

there could be a blockage in the system somewhere and at low rpm's isnt even pressure to bypass it

 

hmm idk where to start lookin for that