cftbll88

I cant figure out what is wrong with my heater i have replaced the thermoast and heater core...You can here the blend door opening and closing and When you first turn the heater on its really hot then it goes completely cold I have know idea what it could be if and also my truck temp gauge only reads on the N or O of normal never runs hotter if anyone know what it could be help Please

BrianH

this may sound lame, but did you check yer coolnt level?

jay anthony

the clutch fan on my tuck was seized so it ran on full and would take for ever
to get the truck close to warm.

And for sure check the coolant level.
Check the rad its self though ( when cold) the line to the overflow box on my explorer was jammed with what looked like rad sealer and I thought my rad had enough fluid.

Good old Bill

What temp t-stat did you install? Are heater hoses hot to touch (both)?

wde3477

The heater being hot at first then going cold suggests to me that sufficient flow isn't going through. This could be due to low coolant level, kinked hoses, or the use of a bargain basement core.

Don't put a lot of faith in your temperature gauge reading, not the most accurate. If it changed readings after the thermostat changeout - perhaps you got a bad or incorrect stat. Hoping you did put the stock temperature back in - which IIRC is about 195 degF??

Good luck and keep us posted.

cftbll88

Well guys the correct stat is in the truck and none of the hole are kinked any other ideas