no heat while idling

[what a mess]

hello all I have an 05 f250 and when I start the truck I have no heat when I start driving I get heat when it idles I lose heat again I have replaced the thermostat and the heater hose with the valve in it and still nothing help would be appreciated

 

[suprdzlduty]

As long as your coolant level is where it should be, it sounds like you've got a headgasket issue...the extra pressure in the cooling system will lock the heater core. Then once the water pump is spinning faster, it will overcome the lock and give you heat.

 

[DEEZUZ]

Headgaskets

 

[what a mess]

that's what I feared!! heh time to buy a 6.4!

 

[DEEZUZ]

Yea good luck with that

 

[silverslug]

I have had A partially plug heater core do the same thing.

 

[yannie]

In winter my 2006 6.0L will warm up while it high idles upon start up but when I start driving down the highway and my speed steadies off then the air starts blowing cold, if I accelerate it will start blowing hot. Same thing when I stop at a light, stop it's cold accelerate it blows hot but once the speed steadies out it blows cold. The engine temperature stays normal all the time and I'm not losing any coolant.


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[Gary]

If it's not puking I'd try flushing the heater core.

 

[what a mess]

I checked my system with a hose it was free flowing =(

 

[morepower02]

Had the same problem a few years back....headgaskets

 

[Jason]

Heater in early September? Tsssss

 

[what a mess]

heater in early September cause I didn't want to get caught with my panties down its goin to be a low of 39 on saturaday