About a week ago the heat in my truck started acting really goofy. Basically, the heat does not get warm until I'm driving at least 55-60 mph. Then, when I slow back down, it gets cool and stays cool again.

Any suggestions? I've had people suggest everything from thermostat, to low coolant, and even low transmission fluid. I've yet to check any of these things because I wanted to hear from you guys first.

Any thoughts? I'm freezin' my nini's off every day.

Thanks.

 

Sounds like the heater core may be clogged or the thermostat may be stuck open. Are you smelling anti-freeze?
Here is a good thread for R&R.

https://www.ford-trucks.com/forums/4...ht=heater+core

 

I would back flush the heater core first.

 

Have you even checked your coolant level???
Running coolant that low is truck abuse!


Other than that, clogged heater core is the most likely suspect.

 

So, it turns out that it was the coolant. There wasn't any in the reservoir.

I fill the reservoir back up thinking that I'm a real jackass. Today (2 days later) I notice that coolant is leaking out from under my truck at a pretty steady rate. I have a gravel driveway so I didn't notice it until I was at work.

What should I check? I looked under the truck but I couldn't tell where the leak was originating. Any help would be greatly appreciated.

 

Coming from the front? Water pump most likely.
Could also be a split hose.

 

Yeah, it's coming from the front. I'm going to crawl under it tonight after work.

Is a pump difficult to replace? I'm decent mechanically, just always been too nervous to touch my truck's engine.

 

If you've got the tools to remove the fan, then it's a cake walk.

Shouldn't take longer than two, maybe three beers, unless you're a chugger.

 

Check the thermostat housing, they tend to leak there and and the lower rad pipe where it bolts on.If you see that the pump is bad it's not to hard to replace .
The cheapest place I found was OReilly's $99.00 Plus tax and core. I would also replace the top rad hose with the one that goes around the serpentine belt and the t-stat. some replace the t-stat housing with a billet piece . If you want to flush the cooling system it wouldn't be a bad time to do that either. You will also need a fan clutch removal tool buy or rent (Auto Zone has the correct one as a loaner ) .