Okay I'm new here and have a f250 2003 v10 I had the diver side head spring a leak and i put stop leak and fix the leak but made the temp go into safe mode.... I got it to my father inlaws shop and fix the Head and replace with new gaskets ,plugs , cin head senor ( no water senor on this truck) new radiator, belt,water pump, oil ,filter on so on. I have drove it a 150 miles and now the temp gauge will go up till the check gauge light comes on and go back down to normal running temp..the truck is not hot most I got out of temp gun was 209....

What should I check now ?????

 

So are you trying to say it climbs to red zone, and then drops back to normal?
Just once, or over and over?
How long does it stay high?

First two thoughts are air trapped in cooling jacket or a sticking thermostat.

 

mwsf250 YES
climbs to red zone, and then drops back to normal....yes


over and over? yes


it may stay up to the red for 5-10 sec. then back down and will make the check gauge light come on!!

how do I get the air out there is no bleeder valve and I have put 2 thermostat in.

any help?
Thanks Will

 

Disconnect the rear heater hose at the intake manifold, and fill the reservoir until the coolant flows out the back of the intake. That should take care of any air. Then keep the reservoir topped up as you idle it and let it come up to temp.

If this keeps happening, I'd check the sensor itself, especially if the coolant isn't really all that hot. Is the clutch fan working right?

 

I got a new thermostat from ford house today and did away with aftermarket one I have drove it 70 miles and no problem so far!


Thanks for Yalls help

Will