Audi VW Thermostat - O-ring - 4 Cyl - 87c - Diesel Engines 2010-2014

2010-2013     A3 4dr Hatchback - Non-Quattro w/ 2.0L 4 Cylinder 16 Valve TDI Diesel Engine
2013-2014     Beetle Hatchback - Models w/ 2.0L 4 Cylinder 16 Valve TDI Diesel Engine
2013-2014     Beetle Convertible - Models w/ 2.0L 4 Cylinder 16 Valve TDI Diesel Engine
2010-2014     Golf Mk VI Hatchback - Models w/ 2.0L 4 Cylinder 16 Valve TDI Diesel Engine
2011-2014     Jetta Mk VI Sedan - Models w/ 2.0L 4 Cylinder 16 Valve TDI Diesel Engine
2010-2014     Jetta Mk VI SportWagen - Models w/ 2.0L 4 Cylinder 16 Valve TDI Diesel Engine

The thermostat controls the flow of coolant based on engine temperature. When you first start the engine, the thermostat remains closed to quickly warm the engine to the designed engine operating temperature. After several minutes, the thermostat opens and allows a variable coolant system flow. This gives the engine the optimum operating temperature, best fuel economy, and performance for all driving conditions. Over time and use the thermostat spring weakens allowing for an inefficient non-designed flow of coolant. This can make the engine run cooler or hotter then designed. If you notice the engine temperature gauge indicating lower then normal engine temperature and your vehicle is blowing cooler air during winter months more than likely your thermostat is in need of replacement.

Also in some cases the thermostat can get stuck closed, this allows for no coolant circulation and can lead to the overheating of the engine. This can cause a blown head gasket or warped cylinder head. If your engine temperature gauge is indicating higher then normal engine temperature more than likely your thermostat is stuck closed and is in need of replacement.