Engine Coolant

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Engine coolant is the key element of the heating system. The normal engine operating coolant temperature is controlled by the thermostat. The thermostat also creates a restriction for the cooling system that promotes a positive coolant flow and helps prevent cavitation.

Coolant enters the heater core through the inlet heater hose, in a pressurized state. The heater core is located inside the heater/vent module. The heat of the coolant flowing through the heater core is absorbed by the ambient air drawn through the heater/vent module. Heated air is distributed to the passenger compartment, through the heater/vent module, for passenger comfort. The amount of heat delivered to the passenger compartment is controlled by opening or closing the heater/vent module temperature door. The coolant exits the heater core through the return heater hose and recirculated back through the engine cooling system.