If your 2003 Volkswagen Golf is experiencing overheating or overcooling problems, it may be due to a deteriorated thermostat. Overcooling problems are oftentimes triggered by a thermostat that is stuck open when overheating problems by a thermostat that is either stuck closed or does not open at the sufficient coolant temperature. Different make sand models of vehicles also employ different thermostats. There are high-ranging thermostats that retain engine operating temperatures at above 2,000 F and this leads the engine to burn up more pollutant and control emission. The life span of the thermostat largely depends on external factors such as the type of engine, load requirements, weather, and others. Pellet type thermostats are commonly used by some cars and the name is derived from the wax pellet and expansion takes place as the engine coolant is warmed. The thermostat of your Volkswagen Golf has the tendency to “stuck shut” as it cuts off its ability to cool off the radiator. It is most prevalent if the engine tends to overheat because water pump fails to perform its task. It is important that your thermostat is monitored in order to avoid overheating of the engine and engine wear out. It is also important that the components of your thermostat must be in tiptop condition so as to perform its task efficiently. Such component is the thermostat o-ring. If you wish to be equipped with this component that efficiently serves your thermostat, make sure that your Volkswagen Golf is equipped with G4030-13854 Aftermarket Thermostat O-Ring. A Aftermarket Thermostat O-Ring featured in our online catalog is sure to be made of high quality materials so you couldn’t ask for anything more.