Denso Coolant Thermostat (DTM83709) Fits: VW

The Denso Coolant Thermostat (DTM83709) matches Original Equipment (OE) quality specifications, which means it is at least as good as, if not better than, the original part supplied with the vehicle.

The thermostat is a temperature-sensitive valve that regulates coolant flow between the engine and radiator. When the engine is cold, the thermostat remains closed to speed warm-up; at a precisely calibrated temperature it opens, allowing coolant to circulate and hold the engine at its optimal operating range. This balance prevents both overheating and overcooling, protecting components and ensuring consistent performance in every season.

Stable engine temperature improves combustion efficiency, helps control emissions and fuel consumption, and reduces mechanical wear. DENSO Thermal Systems engineers develop and validate thermostats using climatic chambers and real-world road testing to verify performance in conditions that mirror how customers actually drive.

DENSO First Time Fit parts meet or exceed manufacturer standards, mount properly with minimal installation issues, and deliver years of reliable service.