Over-heating lead to faulty gauge....

So my thermostat blew a couple weeks ago. I changed it out with a 182. Well now my temp gauge seems to be off. When I start it up, it reads 220 degrees, and then gets warmer from there. Only my engine isn't heating up. Here's my question:

In rare cases will an overheat cause a gauge to go bad? I have no problem switching out gauges, but if I have to I will....

Joel

 

or the new thermosat could be junk...it does happen.

 

Did 'ya install the thermostat correctly ?? if it "exploded" ...where are all the pieces ??? i always put a new thermostat in a pan of water on the stove with a thermometer in it to make SURE it opens as it's supposed to ....even NEW can be bad ,,,,,and --the gauge should be OK .... but ..put a thermometer directly IN THE RAD and see what the temp REALLY is ......see if water is flowing too .....

jersey Skip

 

It sounds like possibly a sending unit for the temp gauge. Does the gauge go to the lowest temp on the gauge when you first turn the key on with a cold engine? If not you could have a bad sending unit or wire resistence in that circuit.

 

I thought it was the new thermostat as well, but my gauge still stays at 220 even before the cold start when all my gauges are on auxilary power.

 

I ran my car completely out of coolant at Woodward last year. It fried the guage and the sender. The needle dropped completely off the end of the scale and never came back and the sender was toast.

 

The sending unit failure makes more sense to me. Thanks.

 

sounds like a wiring/sensor/gauge problem ...... electric gauge ?? disconnect the sensor lead and see if it changes.....and BUY a thermometer ..... like for baking in an oven..they're cheap ...

jersey skip

 

Place that thermometer where? Pull the Rad cap off and check the fluid temp with it? Sorry, this is a first build for me, so I ask a lot of noobie questions. I'm sure most of you understand.

 

Check the sending unit with an ohm meter it should read a resistence when cold and change resistence as the engine warms up. If it does not read any resistence then it is bad (open circuit) . If it changes resistence then you have either an open circuit (wire) to the gauge or the gauge is bad.

 

Good question; Leave the lid on. Lay the thermometer bulb end on a piece of ducktape, put a glob of vaseline on it, then stick it to the top tank of the rad. Run the motor until it's up to over 150 degrees. It won't go there until the thermostat opens. At that point compare the gauge and the thermometer. If you want to find out how efficient your radiator is, do the same thing at the bottom tank. It'll be cooler than the top. Do all this with the motor running at a fast idle.

 

Awesome help guys. Thanks a million.

 

I ,personally, put the thermometer DIRECTLY INTO the fluid in the rad ...that way you see ACTUAL coolant temp...... get one with a BIG head so it won't fall in !!!

jersey skip

 

Probably a Stewart Warner Gauge....................


http://www.jalopyjournal.com/forum/showthread.php?t=79278&highlight=chaz

 

It was on the car when I bought it.. Probably a Vato-Zone especial.....

 

Without knowing what you have for a motor, I'll take a shot.

#1 - A bad ground between the battery and frame and engine. If it were just a bad sending unit, the gauge should read zero or whatever the lowest reading is when the key is on and the engine is cold.


#2 - Bad gauge.


'Course, knowing details would help.