My 94 f-250 Just started overheating today. Needle was buried in the red on the way home. When I got home I went to check the upper hose which was warm and had no pressure. I was thinking it may be the t-stat or the water pump. I took the radiator cap off and the radiator coolant level was about a half inch low. What do you guys think??

Thanks Bob

 

No pressure indicates a leak or failing radiator cap; I know I've had problems with crud keeping the radiator cap from sealing before.

Overheating, I'd probably replace the t-stat. Waterpumps don't usually fail that way; for the pump to break off would require shearing a 1/2" or so shaft.

 

My radiator cap had worn into the radiator filler neck and wasnt sealing but it never overheated.

Have you checked your oil to see if you have any coolant in it from a failing oil cooler?

 

was it overheating, or is the sensor bad?

 

Thanks guys. I'll get a cap and t-stat today and start there. I'll let you know how I make out with them.

 

The idiot guage was buried in the red. I can try replacing the sender.

 

when i see the gauge read hot, i shoot the radiator and block with an infrared thermometer to see what is really going on.

 

I don't have an infrared thermometer so I suppose I should look into getting one.

 

Did the check engine light come on? if not, my guess is bad sensor grounding out, especially if it wasnt boiling coolant.

 

No it wasn't on. It's got a sender not sensor. Only 1 wire going to it.

 

There are two different ones, at least on a 7.3. One is for the gauge, the other is for the check gauges / check engine light.

 

correct. the sensor on the driver side head is for the CEL. i don't remember where the gauge sensor is.
there are only two things that will set the CEL, low oil pressure, and high engine temperature.

 

They are both on the driver's side head/block, right there at the front of the engine. The gauge sender is the 'topmost' one, the switch is further down and larger(I replaced that with an actual RTD probe).

 

Well I got a new radiator cap and thermostat from Ford but haven't had a chance to change them yet due to working stupid hrs!! Hopefully soon I'll get it done!! Thanks for all your help guys!!

 

Needs temp gauge sender, buys t-stat and rad. cap... did i miss something?