Sudden and short overheating

[macboney]

Frequently when first starting out for the day the water temp gauge will go to hot, light comes on and in 2 to 3 seconds the light goes off and the temp gauge goes down. Not loosing coolant to speak of. Have replaced thermostat housing that was leaking from crack and thermostat. I think it might be a thermostat sticking and after first opening works normally. Anyone else experienced anything like this? If so what fixed it? I will probably replace thermostat and put on new gasket/o ring. Just looking for any possible causes I might not be thinking of.

 

[swshawaii]

Sounds like a faulty thermostat. Test it in boiling water and see if it opens at 190+ degrees with an oven thermometer.

http://www.explorerforum.com/forums/showthread.php?t=304165&highlight=thermostat+sticking
http://www.explorerforum.com/forums/showthread.php?t=353480&highlight=thermostat+sticking

 

[JCR]

I am having the same issue lately and a very good friend and excellent Ford Tech is leaning towards it being an instrument cluster problem. When you say a light comes on is it the check gauge light or check engine light? My thermostat- thermostat housing (upper and lower) and my temp sensor are all new within the last 5000-10,000 miles. My temp gauge actually drops to cold just as the temp gets to operating temp and bounces right back up. My check gauge light comes on goes right back off. If I am not looking as it happens I sometimes miss it happening.

 

[pet575]

I'd think that it would be the temp sensor if the thermostat tests out OK. Especially if you just replaced the thermostat.

 

[macboney]

It is the check gauge light