over the last couple of months my ST24 has started to run a bit hotter than normal, the fans still kick in etc and it cools downetc but before it used to sit on the "O" of Normal on the gauge it now sits at "R", and the fans seem to kick in a bit later as well, does this sound like the thermostat needs replacing?

 

Plastic impeller in the water pump disintergrating could be one

 

defo not water pump, had a metal upgrade installed when i bought the car first thing i did

 

 

maybe its just that the weather is gettin a bit warmer or u need to change the coolant to summer mix

 

if in doubt, replace the thermostat, theyre only a few quid, get a genuine one tho as some pattern part ones are incorrect