Thermostat possible problem?

[Ravs1988]

Hello all

Owned the car for just over a year and never seen this before. Car drives just fine. However when coming up to to temp say half way, the temperature gauge then slightly drops and hovers there for about 5mins before going to normal temp. its the slight drop that concerns me.

Anybody noticed this before?
Thanks

C204, 2011, 220cdi, circa 68k on the clock

 

[LostKiwi]

Quite normal on some cars.
It's the thermostat starting to open and releasing cold water into the system.