D6 intermittent erratic water temperature readings

[Shano]

So for a while now our Volvo water temperature reading will very occasionally jump around from showing 180 to 160 then 2 seconds later then 155 then 173 etc. Most of the time after the engine gets to operating temperature it just sits there at 185. It has always shown erratic readings less than 185 - if it was showing reading higher I would be more worried. When it has been doing this erratic reading situation I will go to neutral and then reset by shutting of the engine, pressing the engine switch and turning off the engine main battery switch — which sometimes works sometimes not, other times I just watch it and it eventually goes to 185 and stays there. Anybody else have this happening lately and what was the issue? I’m guessing that the sensor is faulty, or the sensor connection is loose perhaps. Anybody know this sensor is located?

 

[TA_73]

Our 2015 CW with the D6-435 jumps around a little bit when it is below operating temperature but not as much as yours. Once it hits operating temperature it rarely moves. I put it down to the thermostat opening and closing as it warms up but I could be wrong. Has never really concerned me much.