99 over heating when heat is on?

[Crikey]

To day I was driving and heat went cold and engine temp went way up. Pulled over check fluids all good. Turned the heater off and went back down then tried it again turn the heat on and engine temp could have gone past 240 what do you think

 

[sasquatch094]

what color is your oil?? is it Brown or is it muddy looking like?? how many miles on your hoe/burban/yukon???

 

[fyremanpat]

possibley a bad thermostat

 

[Crikey]

Found the problem broken fitting on the intake to the heater hose. Used a saw all blade cut out the old material re-tapped it and put a new quick disconnect fitting in all good so far thanks for the replys