Truck overheating...what is wrong?

[pikestabber]

I have a 2001 Ford Ranger (3.0, V6) that overheats at speeds above 55mph or so and especially if the AC is on. Seems to do fine at 35mph or less (in town driving). If it overheats at a higher speed and I turn the heater on, it backs the heat gauge down, or if I slow down/stop, it recovers quickly from overheating. Suggestions for what is wrong? It is getting more and more frequent (every time now) whereas it was only once every few days at first. Thanks in advance.

[spearchucker]

Plugged radiator?

[Jeremy airjer W]

Check in front of the radiator in between the condenser and the radiator for a build up of debris. Is is not uncommon for a lot of stuff, especially cottonwood and sand to build up in from of the radiator. If you have a blow gun you can try blowing air through the radiator from the engine side to get some of that debris removed. Otherwise if you can get a garden hose in between the radiator and condenser or loosen up the radar to gain access and spray the snot out of the fromt of the radiator you may be able to remove a bunch of the debris as well.

We see this quite often at the shop!

[pikestabber]

Thanks, airjer. I'll give that a shot.