JOHN-DEERE-4045-6068-6090-THERMOSTAT

DZ100553 is the thermostat for John Deere's 4045, 6068 and 6090 engine family, controlling coolant flow to the radiator based on engine temperature. A thermostat stuck closed causes rapid overheating; one stuck open means the engine never reaches proper operating temperature, which on a diesel shows up as poor fuel economy and increased injector carbon build-up over time. Either failure mode is worth catching quickly. Orange.net.za dispatches this part fast, South Africa-wide.