I've noticed that my temperature gauge takes, what I believe is an abnormally long time to reach 90. I know what a failed/failing thermostat is like on a 1.8T AUM engine, as suffered one on my old Mk4 Golf GTi and subsequently replaced the stat myself. Anyways, after performing a quick visual check of the associated bits n bobs, I've noticed my coolant fluid is above the max fill level. Can this be causing the issue? I know the fluid is hazardous and that the system is pressurised (or at least it should be), so I'm guessing elevated pressure, resulting in cracking or leaks throughout the system could occur, right? How should I go about lowering the level? Syphon it out somehow?