truck won't warm up.........

[dave85]

finally put on a new mechanical temp gauge because I thought the other was bad. My truck won't go above 100 degrees.

85 6.9. 371k miles

 

[gatorman21218]

your thermostat might be stuck open. Mine was last month. Do you get heat out of your vents? Take the top rad hose off and then unbolt the part below it thats where the tstat is. A new one is around 30 bucks from ford. Only use a ford tstat

 

[joe_diesel]

It does have anti-freeze?

 

[BigRigTech]

Usually it's a stuck t-stat as noted above, the only other thing I've seen that causes no heat is a blown head gasket....It's actually a common complaint for Detroit 60 series engines in the winter - one of the first signs of a head gasket on it's way out.

 

[dave85]

heater/defroster ............

work fine. Radiator feels hot after warming up.

I'll head to IH and get the t-stat and try that.
Thanks to alll,
Dave