I feel I am going to have to replace one or the other, but, thought I would ask anyway...

When I first start my 92 Blazer s-10, The temp gauge reads fine for a while, then starts its slow creep up. If I gun the engine to get up to speed, it will spike to 260, then crawl back down again to an acceptable range. However, if I stop at a gas station or something, only for a few minutes, and start the truck back up again, it will spike to 260 and stay there for however long it takes til I shut it off again. Is this something I can repair, or do I need to replace the sending unit?

Malachai

 

Do you have digital or regular gauges? If you can get an idea of your actual water temperature and measure the resistance of the sensor the values are 104 degrees F - 1300 ohms, 203 degrees F about 220 ohms. Resistance gets less the warmer the sensor gets. It sounds like you have a sensor problem. Have you cleaned the terminals and connectors in the circuit? You can also ground the wire to the sensor and your gauge will read hot to check the gauge.