Water temp gauge test?

[deacon]

I suspect that my temp gauge is reading too high. Everything I have been checking with the cooloing system is leading me in this direction. Has anyone had the experience of finding it to be off? Does anyone know of a test procedure for this gauge and or sender? Thanks.

[pooldoctorstl]

Remove the radiator cap (COLD ENGINE) then put a cooking or meat thermometerin the radiator. Start the engine and let it warm up. The gauge should match or be close to the thermometer once the thermostat opens and coolant begins to flow. Don't forget to clean the thermometer!

[So Cal Mark]

unless you have a variable resistor to use, the only gauge test is to ground the sensor wire and see if the gauge is pegged

[deacon]

Remove the radiator cap (COLD ENGINE) then put a cooking or meat thermometerin the radiator. Start the engine and let it warm up. The gauge should match or be close to the thermometer once the thermostat opens and coolant begins to flow. Don't forget to clean the thermometer!

Interesting. I hadn't thought of that one. Kind of a simple way to check the gauge. I'll give it a try

[mbouse]

Don't forget to clean the thermometer!

especially if it is a rectal thermometer !!

more accurate and safer would be to buy an inexpensive laser thermometer and get a reading off the head AT the sensor and compare that reading to the gauge.

[manoa matt]

Since the gauge reads resistance, I'd first clean all the contacts and connections within that circuit to eleminate corrosion as an additional source of resistance.

If you check the wiring diagram there is an inline resistor wired into the circuit. It should be in a holder similar to a fuse holder up under the dash by the ignition switch. Clean those contacts too, but don't break the resistor wire.

[deacon]

All good suggestions and thanks, but I am stil trying to get over the idea of the redtal thermometer........