Mechanical Water Temp Gauge Failure

[BrianX128]

I've had a mechanical water temp gauge in my IDI for going on a decade now. I put it in the overtemp port, I drove the truck yesterday morning and it only read 120. I wondered if my thermostat stuck open, I couldn't check my heat because I have two three way ball valves installed to isolate the heater core in summer. When I left work I turned the heat back on, and was surprised to find it was hot as ever. Looked at my gauge and it wasn't reading anything. Did the line crack or something to the gauge? I've never had a mechanical temp gauge fail. Had an oil pressure gauge fail once, those are a lot easier to diagnose when you have to shut the truck off and shove a cup under the gauge.

 

[Nero]

Its possible the sensor failed. If you have a temp gun, laser it at the sensor location and see if the reading is close.

 

[Clb]

Senders do die....

 

[IDIBOBS]

Yup. With how cheap and easy gauges are to change I’d just grab a new one. That’s one gauge I don’t want to live without.

 

[THSIM9]

I had one fail as well. It was a cheap Bosch mechanical gauge and it just quit working one day. I still had the stock gauge at the time which was reading so I knew it was just a sender failure.

 

[IDI-IKE]

A mechanical temperature gauge is nothing more than a pressure gauge. The bulb the goes in the water jacket is usually filled with ether as temperature increases the ether expands and makes more pressure, a copper line connects the bulb to the gauge. When the copper line cracks or springs a leak at a connection the temp gauge will go dead. Since it read 120 it probably still had some pressure left to push the gauge to 120 but during the day the rest leaked out as it sat there under pressure hence it not reading at all after. Go on surplus center they have Isspro mechanical temp gauges at a killer deal, Isspro is about the best you can get.