ford heating/overheating problems

[sparky27]

1999 Ford F 150 4.6 v8 218,000 miles

Okay, where do I begin? I have been dealing with this since november. Started out with not having any heat. I started with replacing the t stat. That made no difference. Next i took it to my mechanic. I was told my engine is rusting from the inside out, debris was clogging my heater core. He blew it out and i had heat for almost two weeks. Took it back had it blown out again, heat for another two weeks. Then on one of the coldest days of the year took it to one of the big chain stores near where i was working that day, had it blown out again. This time i had zero heat, actually was blowing ice cold air. They told me my water pump was shot. For $400 they would replace it. On my way home from there my temp gauge was reading hot, close to redline. That was a first. I called a mechanically inclined friend, he helped me replace the water pump. It solved the overheating problem, but not the heating problem. I now have no heat and after about five minutes of driving my truck starts to overheat. What is the next step in trying to fix my truck?? My friend suggested getting a t stat that opens at a lower temperature if that makes any sense. Also when i initially put the t stat in in november i never purged the lines, not sure if that matters or not. Any ideas or thoughts from you guys would be great. Thanks alot.

[sparky27]

Oh yah, forgot to mention. Also had a complete cooling system flush done by another mechanic abot a month ago.

[walleye29us]

I would be thinking, Heater Core....Just my opinion..Good luck...

[6arrows]

i had a 1997 that did same thing until one day a mecanic told me to take radeator cap off and let it run with heat on full blast add coolent as needed and get all the burps out you will see it bubblen when that stop u mite be ok

[Jeremy airjer W]

Sounds like you need to burp the air out of he system AND bite the bullet and replace the heater core!

[sparky27]

Thanks alot for your help/advice. Another question. What is a good way to "burp" the lines, and do you think the heater core has anything to do with the overheating problem? Pretty sure the heater core is pretty spendy, may need to save some pennies before getting that done. would like to be able to drive even without heat.

[Jeremy airjer W]

with the engine cold remove the radiator cap. Top off the coolant as necessary. start the engine and allow to idle until full operating temp. topping off the coolant as necessary. Once the stat has opened and you feel the fan pushing hot air install the cap. You should be set.

[fishing tech]

If there is that much [PoorWordUsage] that the heater core keeps plugging you may also have a radiator that is plugging up also. Does the temp slowly keep creeping up to the overheat line or does it jump up in a short period of time?

[fishing tech]

I did not know that c r a p was a bad word. Sorry

[SkunkedAgain]

Fishing tech is right. If stuff is plugging up your heater core, it will likely plug up radiator too. Coolant runs between your radiator, engine, and heater core. If hot coolant isn't making it to your heater core (to heat your cab) then it also may not be making it to the radiator (to cool your engine).