All, I'm new to this forum and looking for some assistance.

I have a 1996 f150 5.0l and my heater is not functioning properly.

Just had an intake manifold gasket replaced (leaking) at a local shop. They replaced the gasket, flushed the cooling system and replaced the T-stat (195).

When I got the truck back the heat was not working and blowing cold air only out of the defrost area.

I found one vacuum leak (patched it), parked the truck on an incline and ran it with the radiator cap off in an attempt to purge any air that may have been trapped in the heater core.

Now vent/defrost/floor routing is good but the air is only hot for a short time (after running for5-10min) and becomes luke warm. I can turn the heat off for a few minutes then back on and it’s hot again but quickly fades to luke warm. I've read other post about the temp actuator not working correctly, but when I adjust the temp to cool it really cools off. Today when I got home I checked the heater core hoses. One was hot the other was warm not hot like the other (noticeable difference in temp).

I plan on replacing the original hard plastic vacuum line this weekend with rubber tubing in hope that if there is another vacuum leak that will take care of it, but I’m not sure if this is causing my heater problems.

Any thoughts?

 

FYI, I solved the problem. I flushed the heater core with a garden hose. Lots of black gunk came out. Now the heater will burn you out even with the outside temp in the teens and twenties.

After fixing the heater I changed out all the plastic vac line with tubing. Very easy task.

 

Well shoot. Glad I could help. LOL. Guess you really didn't need to ask huh. Glad you figured it out. It makes you feel good when you can solve things like this. Who needs a mechanic anyway?

 

well put

Did you know there's a 10 character minimum limit for messages? It wouldn't let me just write "well put"