'97 K1500 Temp Gauge Reading

[bcrooms]

Yesterday I noticed my truck's water temp gauge has started to give an inconsistent reading.

 

While I'm driving the temp gauge shows below 210, closer to the mark between 100 and 210.  When I come to a stop for a few minutes (red light, etc) the temp seems to increase back to 210 and at times goes above 210, but not by much.

 

When I resume driving the temp drops again.   I know it's been colder than normal lately in our area but the last few days it has been in the mid 40s to low 50s.

 

Could this be relative to the water pump not operating as it should or temp sensor / sending unit?

[richard wysong]

It's probably fan related but it sounds like you may need a thermostat first. Temp should stay steady regardless of speed but may rise stationary if the fan isn't working properly

[bcrooms]

6 minutes ago, richard wysong said:

It's probably fan related but it sounds like you may need a thermostat first. Temp should stay steady regardless of speed but may rise stationary if the fan isn't working properly

I can also feel the heat in the cab get much warmer if I have it on while this is happening.  I can also feel it cool down.

[richard wysong]

Tstat first, easy job, 2 bolts and a hose