Front Heater Core Noise

[pzy3339]

This issue started last year, but was less severe.

If I start my truck to warm it up and let it sit and get hot the front heater does not produce any heat until I start to drive.


The front heater core does not seem to be getting any coolant flow at idle. When I accelerate I can hear the coolant flowing through and heat starts.


This is not an issue with the rear hvac system.

Is there some type of flow control valve for the front heater core?

Thanks

 

[Flag Gibby]

Yes there is a valve under the hood that is opened when you put the system in heat mode that allows hot coolant to circulate through the heater core. I guess that it could be sticking partially open, but goes fully open when the system flow increases. I also recall reading about some vehicles (may have only been Ford Flexes) that had issues with the motorcraft gold coolant causing heater cores to plug up with deposits.

 

[pzy3339]

I also recall reading about some vehicles (may have only been Ford Flexes) that had issues with the motorcraft gold coolant causing heater cores to plug up with deposits.

I have seen gelled coolant on the radiator cap. I could believe it is clogged up. Cant imagine its fun to pull the heater core out though.

 

[sgully67]

Check the coolant level. Low coolant will cause this problem.

 

[08Exploder]

I would first do what flag gibby said with the valve make sure it's open I would check to make sure it's functioning when you switch hot to cold then see if it's getting warm also checking coolant level in radiator COLD before running it make sure full and if all else failed before I would say cloged heater core I would remove both hoses atach a garden hose to one and flush out the core and if water flows st s good rate then you know your core is decent. I used to have to do that on my dads old Taurus every winter and he would be fine till the next winter.

Tom