The optional engine coolant heater (RPO KO5) is designed to warm the engine coolant in the engine block area for improved starting in very cold weather (-29°C/-20°F). The use of the coolant heater helps reduce fuel consumption when a cold engine is warming up. The engine coolant heater coil uses a 110 volt AC external power supply.

The coolant heater consists of a small electrical heating element and block inserted through a water jacket hole in the engine block. This heating block is precisely machined. The heating block uses a rubber O-ring to seal the coolant passage. A weather shield on the end of the cord is provided to protect the plug when not in use. Care should be taken to secure the extra length of cord when not in use. The cord should be inspected periodically for serviceability.