Thermostat

[Trevor Triumph]

We drove from Phoenix to Prescott on Saturday and back! Darn hot! I actually passed cars on the big hill between Wickenburg and Yarnell! I paid for it with a boiled over radiator. The temp gauge did not register all that hot but we lost coolant. As soon as we added more the gauge indicated a big drop. I noticed that the gauge and rose and fell seemingly unrelated to work the engine was doing. Do you suppose I need to replace the thermostat? I might add that less than a monthago we were in Flagstaff during a snowstorm and the gauge hardly moved from the coolest position. T.T.

 

[achtungeveryone]

are you sure you got one in there?

 

[philman]

maybe you have some kind of air bubble in the coolant system causing a surging of coolant -- hence the cycling of the temperature.

 

[Guest]

I had problems with my temp gauge not seeming to agree with what was going on with the car at the moment also. Turned out my sending unit for the gauge was bad, was reading lower than it should have and not responding to changes as rapidly as it should have. If the unit for your car is not that expensive it might be a good idea to replace just for the heck of it.

 

[Geo Hahn]

I've mentioned before, but this is the thing for pinpointing overheating IMO:

https://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=22-325

Meanwhile, a look at the tstat in some boiling water might be instructive. FWIW, the times I've have sending units fail they have read low but never had one that fluctuated.

 

[dklawson]

The non-contact thermometer is indeed a handy tool.

I know this turns the stomach of most LBC owners, but when you have no faith in your Smiths gauges, buy a capillary tube VDO temp gauge off eBay and use it at least long enough to regain some confidence. You can always put the Smiths back in later.

BTW, I'd take that thermostat out and put it in a pot of boiling water to see if and when it opens. If you buy that RadioShack gauge (and use a dark pan to boil the water in) you'll be able to tell what temperature the thermostat opens at.