Heater Problem

[gcally]

I need some help! I have a 2006 GMC Sierra 1500 crew cab and the heat only blows hot when I am driving down the road.

 

 

For example if I start my truck in the morning and let it warm up to operating temperature the heat will only blow cold air. As soon as I start to drive down the road the heat will blow hot air after driving 10 seconds.

 

I already replaced all 4 blend door actuators (what a pain in the ***) and heater controls. Everything works fine once I start driving down the road. All 4 blend doors are working fine. I cannot think of what else I should check.

[05silvycrew]

check your coolant level....this happened to me a couple weeks ago. the only time the heat would blow (even with the engine at full operating temp) is when I was accelerating down the road. if i coasted or idled it went back to blowing cool air. turned out I was a half gallon low in the resevoir tank embaressing. first and easiest thing to check.

[gcally]

check your coolant level....this happened to me a couple weeks ago. the only time the heat would blow (even with the engine at full operating temp) is when I was accelerating down the road. if i coasted or idled it went back to blowing cool air. turned out I was a half gallon low in the resevoir tank embaressing. first and easiest thing to check.

 

 

It is a little bit low I will try it and let you know.

What kind of rad fluid should I use? I think the truck still hase the stock stuff in it (red in color). Can I mix different kinds of rad fluid.

 

Thanks Greg

[jrod332]

Use dexcool only. dont mix with regular antifreeze. the doesnt matter, orange, green, red, there all the same.

[gcally]

Use dexcool only. dont mix with regular antifreeze. the doesnt matter, orange, green, red, there all the same.

 

So you are saying that I can use any dexcool wether it is orange, green, or red and mix it with my stock rad fluid.

[bossier62guy]

Use dexcool only. dont mix with regular antifreeze. the doesnt matter, orange, green, red, there all the same.

 

So you are saying that I can use any dexcool wether it is orange, green, or red and mix it with my stock rad fluid.

 

 

Every dexcool I've seen is orange in color....it's a trademark I do believe.