My Gauge when not in traffic just sits after the left hand side white block, when in traffic moves to the O position in Normal and when stopped rises just below the M.
When going around a sharp left hander the gauge sticks on the left; until I go over a bump it then goes back. I Guess I have a sticky gauge, but is the temp reading ok when not sticking? I am not loosing any water or oil and the heater works ok-ish though it is a bit cooler on fan pos 4.