You got something there. That's the sound...it sounds like a door slamming, or at least trying to close when I turn off the heat.

Maybe the door is stuck open and it can't close (or visa versa) and therefore causing the air to not blow through at a high pressure?

Bear with me for a moment....what if it is the blend door actuator?Does this blend door actuator have anything vaguely (yes jumping on a limb) to do with 4x4?

 

No, the blend door actuator is electronic.

If you also have a problem with your 4wd, then I would be looking for vacuum leaks.

 

Okay. So the heat wouldn't be related to a vaccuum leak (that's where I was going with that thought).

I want to fix the heat once and for all. Then I will try to find a vaccuum leak.

I'll let you know the solution.

 

Iheara *creak* *pop* from under the dash - passenger'sside. It happens when I turn on the heat on highand then off. This leaves me to believe the blend door might be the culprit.

 

Intake valve to the heater core is registering 158 degrees.

Outtake valve from the heater core is registerin 68 degrees.

Heater Core = $95 part.

Labor = 9 hours!!!!

Having heat = priceless.

What more can I do but fix it and move on???