Engine Cooling System: Engine: Thermostat: Operation: Diesel

The thermostat starts to open at 88°C (190°F). Above this temperature, coolant is allowed to flow to the radiator. This provides quicker engine warm up and overall temperature control.

The same thermostat is used for winter and summer seasons. An engine should not be operated without a thermostat, except for servicing or testing. Operating without a thermostat causes other problems. These are: longer engine warm up time, unreliable warm up performance, increased exhaust emissions and crankcase condensation. This condensation can result in sludge formation.