BMW Engine Coolant Thermostat - Wahler 11537601158

Product Information

If your BMW is experiencing cooling issues, the thermostat may be to blame. Most thermostats fail in the "open" position, preventing the engine from reaching proper operating temperature—causing the engine to run rich and potentially leading to carbon buildup. In rare cases, a thermostat may fail closed, causing overheating and risking severe engine damage.

Thermostats regulate coolant flow, staying closed when cold to help the engine warm up, then opening to maintain correct operating temperature. Always install the thermostat with the jiggle pin bleed valve at 12 o'clock where possible.

For many vehicles, multiple temperature ratings are available, affecting when the thermostat opens. In extreme climates, choosing the right rating helps maintain ideal engine temperatures.

Common thermostat failure symptoms:

• Overheating engine
• Engine not reaching optimal running temperature
• Radiator fan not engaging