I have a 97 f150 xlt 2wd with 69,000 miles 4.2 I have not had a chance to look in to it yet, but the last 2 days on my way to work I lost my heat. Ii have heat as soon as the truck warms up, but drive it 5 minutes and it starts to blow cold. any ideas? Just thought I would toss it out here before I go tearing in to it.

thanks

G

 

Have you checked your coolant fluid level? Are you aware of the recall on the 97-98 4.2 V6 for the leaking gasket issue? Sounds like you may be a victim of this recall. Check it out soon to avoid hydro locking the engine!

 

He might have a leaky headgasket issue... but theres a slight chance that might be the cause.

I am thinking along the lines of a thermostat gone bad or something clogging the heater core.

Now if it had a leaky headgasket, check the coolant for oil. Now if there is oil mixed with the coolant, it might be messing up the thermostat or clogging the heater core.

 

please dont take advice from this fool.

 

Is there moisture under the heater vents inside the truck or getting a coolant smell inside the truck? Sounds to me that the heater core may be going.
Rob

 

Not even sound advice? That's better advice than you have given here.

The hydrolocks were due to intake manifold gaskets, not head gaskets. There never was a recall, just an improved gasket set. Engines built before 1/15/08 were affected.

 

Do you mean 1/15/98?

Anyways, thanks for backing me up glc...

 

Doh! Yep.

 

Try an Coolent Flush and if the passenger side floor bored is wet then you have a leaky heater core. Try and take it or and blow air though the lines while its submerged in water. i had the same problem and its a 100 dollar fix if you do it yourself.

 

Does the temp gauge go to hot when the cold air comes out, then drop back down when the heat comes back? If so, you are losing coolant. Most likely from the intake gaskets. Look and see if the passenger gasket is a yellow color and the driver's side is black. If you have the yellow one, replace the lower intake gaskets NOW! You are at the mileage where these things go bad. Get parts from Ford only. Also replace both the IMRC bushings at the same time.

 

Hmm... I wonder what the OP's outcome was... ?!

 

Everytime I ahve had this issue it was the thermostat.