Soicant figure out why my 94 f150 302 is not getting anywhere near operating temp. I took the t stat out twice and tested it. Works great.I put it back in and leave the outlet hose off wile I put in some coolant. I can see it seeping through the t stat. And it is tight. So please help. No heat.

 

If it's running cold I'd put a new thermostat in no matter what it looks like. Then you'll know for sure.

 

Are you judging temperature by the factory gauge? Because they usually read cold. Heater problem is something else.

 

It never gets off the c. After about 15 min, it will start to climb, but then I give it some gas and it will drop all the way down to c. Or sometimes below c, wich is weird. Isn't the t stat suppose to hold back the coolant till it opens.coolant like I said, it looks like it is some how going around the t stat as I start to pour some coolant in. I will leave the upper hose off and as I pour some in I will watch it come through the t stat. The t stat does have a little hole in it that was manufactured and it has a little piece of metal that goes through it and kinda just hangs there. I think it is coming through that. But doesn't that defeat the purpose. I am confused.

 

That's so if the thermostat gets stuck shut it won't overheat as quickly. Replace thermostat just because. You've probably spent more in coolant pulling it twice.. than getting a new one once.

 

That is a new thermostat. Is it possible I could have it in backwards. I just now thought of that. I couldn't remember which way it went in so I just took a wild guess.

 

Spring goes towards the engine.

 

Oh really. That would be my problem then. that's funny I have the spring facing outward toward the hose. I guess I better turn that around ha.

 

Yep. The spring needs to be in the hot fluid so that it is activated and opens up to allow the coolant to flow back to the radiator. Simplest way to think about it.

 

Mine runs below the C. The gauge isn't accurate.