HELP - Problem with Heater and Thermo Gauge

[AlabamaDan]

Help guys!

First let me say Merry Christmas and Happy New Year. I haven't been around much lately. They're working my butt off here at work and kids keep me running at home. But I lurk occassionally and need some help.

I've got a problem with my 94 Q. I started noticing my temp gauge running hot the other day - almost all the way to the very top and the heater was on blowing cold air. Then as I got on the highway and RPMs got up around 2500 or 3000 something happened and the heater all of a sudden started working and instantly the temp needle dropped to normal. Then as I got off the highway and started coasting it reversed itself. What's up? Do I need a new thermostat?

Thanks ahead of time guys.

[yodawill2000]

Have you checked the coolant level ??My ole' truck used to do that when it was WAY low.

[AlabamaDan]

Have you checked the coolant level ??My ole' truck used to do that when it was WAY low.

Yeah coolant level is fine. In fact I put some more in it and it it was over full making a mess on the garage floor.

[96Qowner]

First thought is thermostat, but Dennis said this:

Q thermostats fail open and don't let the coolant warm up............common condition in winter.

zerothread?id=205495

Still, can't hurt to change it out.

[qship96]

waterpump not circulating coolant through engine { hot} and heater core{cold}

[goody90q45]

Is the engine fan running at idle? Fan clutch? Still got 3 belts?

[AlabamaDan]

Still haven't solved this problem, but I have another possible cause. Last night when I got home I smelled a burning rubber smell, like a belt. What if one of my tensioners has gone bad and isn't turning the water pump consistently? Then when I get up to higher speeds it does turn it some? I haven't heard any squeeling.

Thanks guys.