Water Temperature Gauge Started to Read Low

[Petronella]

After 7 years with Petronella's water temperature gauge reading a steady 178F, on Thurs it started to read 155F consistently instead, with occasionally fluttering 10F either side of that. How can this be and should I be worried? I could understand it reading hotter but not cooler. I don't like it when things change for no reason.

Other possibly pertinent points are:

- Water is coming out of the exhaust as usual (maybe I should check the temperature of this water).

- The connector on the water temperature sender was a bit loose. Replacing it seems to have stopped the fluttering but not change the underlying low temperature issue.

- If anything the heat exchanger feels hotter(!) than usual rather than cooler (though the outside temperature was back up in the high 30Cs at the time).

- The engine sounds just the same as usual.

We only have to survive three weeks and 200 miles before we return to our home base in Kas (Turkey) when I can take a closer look at things. Meanwhile, what things can I check easily without increasing the risk of making things worse?

Thanks in advance.

 

[DickB]

Maybe a stuck thermostat on the primary circuit. Stuck open or a broken spring would leave it fully open. No problem but the engine won't run quite so efficiently. Cheers

 

[VicS]

Double check all the connections on the temperatre gauge circuit.

The way forward then is to check the engine temperature .. Infra red thermometer ????

If the gauge reads wrongly then it has to be investigated ...

If the engine temperature is genuinely low then test/replace the thermostat. Since this will require draining or at least partial draining of the system maybe leave until the next routine coolant change.

 

[Petronella]

Thanks

Thanks guys. As I thought and hoped it sounds as though we should be OK carefully coaxing P along for the rest of the season.