my 1997 ford f150 4.6 triton runs hot after 1 minute of idleing I changed the two coolant sensors,flushed the radiator, and changed the thermostat.
I also went to have a diagnostic done at two diffrent places and nether one could get a reading any help is appreciated thank you

 

Since you took the system apart to do a flush it's possible the engine is air bound. It's also possible the water pump impeller broke loose from the shaft and no coolant is flowing.

 

thanks alloro I will check that out any recommendations on how to get the air out? excuse me if that last question sounds dumb

 

Did you do all the service items in response to the overheating, or did the overheating start after all the cooling system work? If the overheating started AFTER the thermostat replacement, I would suspect it is installed backwards.

 

Loosen the t-stat bolts and add to the radiator until coolant leaks out at the t-stat, then tighten the t-stat bolts.

 

i did service in response to overheating

 

ok replaced water pump added new coolant sensors,after a overnight cool down i started the truck 30 seconds and coolant hand shoots to hot drive around for 30 minutes than park truck top radiator hose hard as a brick it stayed that way for an houri opend the over flow jug and hose went back to normal any help with this would be appreciated

 

I don't see how the gauge can be in the red zone in 30 seconds. You would think with new pump and full of coolant, it would take several minutes to raise up ?? ....... I think I would take the thermostat OUT and leave it out for a test. Start with the overflow cap off and see if your getting excess exhaust gas out the top ? 30 seconds is DRASTIC.

 

Are you sure the gauge is working?

Do you have access to a non-contact thermometer to measure temps of hoses, etc?

I have also left radiator cap off and stuck a thermometer in to check temp...

 

yes guys my mechanic used his thermometer and all the temps checked out ok i removed the thermostat when i flushed the engine and never put it back in.how can i tell if excess gas is coming thru the over flow jug?

 

also when he unpluged the coolant sensor the gauge went back down to cool

 

you should see bubbles comeing up thru the overflow if there is gas... also the tank might surge and BURP out antifreeze..... of course, the tank level will expand and some fluid might come out normally after several minutes with motor up to temp.

 

there is no bubbles other than the natraul flow like the water pump is pumping.
also when it runs hot it does not run out the overflow the top hose ges hard as a brick like something is blocking the flow,when i relieve the pressure by slowly opening the cap on the jug then the jug fills and the hose goes soft.

 

water goes from the thermostat, thru the top hose into the radiator.. If the top hose is ALWAYS HARD, it sounds like your not getting flow thru the radiator, that it is deadheaded......... I would remove the bottom hose and see if you can pour water thru the top hose , thru the radiator, and out the bottom... it does sound like something is plugged in the hose, in the radiator, or bottom hose back to the pump.

 

thanks steve(iii) yes i can pour water through