Coolant Gauge Accuracy?

[ed1948]

My stock 305 86 MCSS runs well even though the temp gauge reads one third of the scale. I thought convention was that all gauges are calibrated to show normal conditions with the pointer at about noon on the gauge face.
Where does you gauge point point at - one third or one half of gauge rotation.

 

[TURNA]

The factory gauges have always been hit or miss.

With the car warmed up take both hands and push and wiggle the gauge cluster see if the gauges needles "jump"

That or someone removed your thermostat.

 

[airboatgreg]

factory gauges are not that accurate. You may have a faulty sender which is common. A stuck open thermostat or not there as mentioned by Turna. If you have an infra-red temp sensor(If you don't buy one as they are invaluable) Point on warmed up engine on the t-stat housing. Should be a couple hundred degrees or so.

 

[pontiacgp]

the gauge is just a ohm reader so they don't usually fail. If you know the part number of your sender you can finds a chart online to tell you what the ohms are at certain temperatures so you can test the sender. I'm not sure about this but with the computer if the engine does not get up to operating temperature shouldn't that throw a trouble code?

 

[ed1948]

-checked sender resistance @ cold = .5 ohm
-felt thermo housing = when it warms, hose is cold (thermostat appears to be closed)
-just before thermo opens, dial shows 1/2
-then needle drops to 1/3 as engine is warm(it's metric and there is a gap between 40 and 105 degrees celcius)
I suspect the sender may be off and I'll check the manual for specs once Father's Day celebrations are done.
I had the gauge panel apart during the winter and confirmed all connections were good.