i have replaced the thermostat, and i get good heat and it never over heats. the water temp gauge on the dash only goes about 35% of the way. bad sensor? how do i replace it? also i have a cel that comes on everytime i drive and stays on for 2-3 minutes, how would i check that? i know how to check a code if its always on but this is intermittant... thanks.

94 f150 5.0

 

Codes will be stored even with the light off.
If you don't have a code reader you can learn how to do a self test here:

Ford Fuel Injection How To Run a Self-Test

 

My gauge after heating never pass the N letter. Bad sensor too or its ok? I touch the hoses when engine is hot and they are hot but ok, never boiling and water level perfect.

 

Disconnect the wire from the sender and ground it to the engine.
Does the gauge go full scale?

 

Did you put a 195 thermostat in?

 

I don´t know what thermostat have. I own the truck 2 months ago.
I´ll do the test of grounding the sensor. But the sensor have 2 cables. Ground one of them o make a cable by pass between them?

 

The sender only has one wire and it pushes on and pulls off.

If it has two wires to it you are at the wrong place that is the ECT sensor for the computer.
If you ground one of them you may burn up the computer.


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No the dash gauge sensor has 1 wire, it's right in front of the #5 injector on the small block V8's.

 

But i have the I6 300. You know where is in this engine? Thanks a lot

 

Yes it as in the photo below:

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Ok its clear now. I´ll do it after work today. But in your dash, the gauge reaches the middle?

 

Sometimes.

 

Anywhere between the N and R is fine in my experience. As long as you have a 195 stat in there and the gauge is consistent don't worry about where it ends up exactly.

On the 300 the temp sending unit is underneath the #6 exhaust port. It can be a real pain to get to.

 

i dont have the 'normal gauge', i have cold to hot, and its never halfway. 302 5.0...

 

I put an aftermarket mechanical gauge on my 93 F150 with a 300 and when the stock temp gauge gets around O, my real gauge reads 205. In the winter it would hardly get to the N and that would be right at 195. I got it up around the A one day and that was at 220.

The gauge reads really low from the factory, but im not sure how accurate it is. The stock location only take the temp of the water jacket and not the coolant after it goes through the head, and when i put my Mechanical gauge in the stock location, it was so close to the exhaust that it would throw the reading way off. I imagine the stock gauge might have similar issues, but they seem much less noticeable and hard to detect. I moved my mechanical pickup to my heater hose coming of my t-stat housing. It always has the hottest water and give me a good idea of how hot the engine really is running.