97 F150 with a 4.6. long story short its been giving me issues with heat lately and coming into winter we need it. windows fog up until truck is very warm. im putting that down to a heater core leak and i should clarify its more than just the normal fogging due to the cold.

here is the main problem i have though. my temperature dial in the truck if you turn it all the way to full heat it blows cold when engine warm and running but if you turn it back a little bit it will blow heat. could this be due to a old thermostat? trying to get this figured before i do to much. seems previous owner stripped one of the thermostat housing bolts really badly so before i go fight with that to much it would be nice to know if thats really the problem.

suggestions on quick fixes for the heater core would be appreciated. don't know if there are but its a good farm truck (best in the fleet haha) and sadly don't have the time right now to change the core

 

I would replace the thermostat first. Quick 15 min fix for less than 20 bucks. That would simplify the problems down to the heater core water pump and hoses. Gasket could be bad as well. It works on pressure. I had a similar issue this year.

 

ok ill give that a try. we can eliminate the water pump as i changed that this summer. but yes ill go outside and try my luck with that stripped bolt and we'll see if that changes things.

 

Let me know how it goes. I'm actually cleaning mine as we speak

 

k update got the old thermostat out. was not fun but its out. the new thermostat i picked up is bent. joyful. went to town and seems the only store open that would have them doesnt have the gasket so im shut down for the night. tomorrow starts the battle again

 

ok update. and im thoroughly confused. i installed a new thermostat. started the truck up. the heat is ok but not great. ive installed some thermostats before that when the vehicle was warm and you put your hand up to the vent it almost burnt you kinda thing. this is nice and warm but not like it could/should be (as i see it) i installed a 192 temp thermostat. anyways the trucks heat gauge seems to be working correctly so far but might be to soon to really tell.

the problem i now have is it is blowing a mist out of the vents. i went and checked the truck after it ran for about 15 mins and the cab was almost fogged out. there was no mist before with the old thermostat and the heat is comparable. what could this be? im guessing the reply will be heater core but oh i hope its not. to my understanding it is quite a process to change that out.

thoughts?

 

More than likely heater core. Could try a good flush

 

bothersome. ok now how big of a job is that to do?

 

It's a big job I used to install factory a/c into those trucks every day and I would have to take the whole dash out. Get your self a little bucket there are tons of screws to remove