[strenge]

I've been having problems with 2011 F250 6.7L diesle. The first thing I noticed maybe a couple months ago on a trip to the store (maybe 2.5 miles one way. When I almost got there the heater was blasting out really hot air, hotter than normal. On the way back home there was no heat and only cold air. This happened once more later on.

Then a few weeks ago I went on a 30 mile trip and the truck overheated when I got back to my town. I noticed then that the heat wasn't working then either. Same thing happened on a shorter 7 mile trip a week later. I noticed the heat Guage wasn't pegged all the way in hot, but would fluctuate up and down slightly.

Is this a thermostat issue or something else? I'm not very experienced with working on engines yet...

Thank you!

 

[TKR]

Hello strenge and welcome to the forum from N.E. Indiana!!! I'm just asking, but did you check your antifreeze level? Low level could cause the problem your having, or like you said the thermostat! Good luck!!

 

[strenge]

Hello, TKR! The antifreeze level looks okay. Is the thermostat something a car novice can replace by himself?

Thanks!

 

[TKR]

You have to drain coolant low enough so you can remove the upper hose. It has a clip at each end of the hose that you have to slide to get the hose removed. Then there are I believe 3 bolts to remove to get the thermostat housing off. It is a dual thermostat. Go to you tube and watch the video from PowerStroke Tech Talk w/ARod. You'll see what I'm talking about.

 

[strenge]

I'll check it out. Thanks again!

 

[powerstrokeshellback]

which cooling system did you check? there are 2 on the 6.7s...

 

[strenge]

I checked them both. They were at or slightly below the cold level.

Thank you!

 

[powerstrokeshellback]

if the heat works better with higher RPMs it could be a slipping water pump.
generally if you have no heat at idle, its a lack of coolant.

however, with your issues, i would be tracing everything in the cooling system. if you arent losing coolant, which would be a normal cause of your symptoms, you have issue(s) elsewhere.

you didnt mention the mileage on the truck but being a 2011, it might be time for a new water pump, thermostat, etc.

 

[eyearemekanik]

I don't know if you have one or a buddy but pressure test it. Get it up to operating temp, shut it off, connect pressure tester adapter and gauge then pump it up to the psi rating on the cap. Let sit over night and see if you A have a pressure drop and B if you have visible signs of coolant leaking. But, just so you know, I recently replaced an engine assembly for a customer that had the water pump impellers fracture on the inside causing it to overheat and ruin every seal known to mankind.