Wayward temp gauge

[Ronaro]

So after around ten days of sitting unused I took the Ro for a little drive. All was well until after around half an hour when I noticed a usually rock steady temp gauge fluctuating between quarter and it’s normal position. Having stopped and checked both the coolant and oil levels (both are spot on and no leaks) it then went back to its normal position. Since then it struggles to go above the quarter mark but then when I look again it is on its usual mark. The photo is where it usually is.
Could this be the thermostat or a dicky sensor - or something else?

[Ronaro]

Thanks for the reply. This is pretty much where it hovers before going back to normal.

[Ronaro]

Agreed. Is it easy to get to as I’m not entirely sure where on the LS1 it is located?!

[Ronaro]

Thanks mfp

[Ronaro]

mfp is this the sensor in the centre of the photo?

[Ronaro]

I meant to update this ages ago, but after a couple of good runs it righted itself and now stays firm at its correct position. I guess it didn’t like me going away for a bit