The Jeep Grand Cherokee Repair Manual 2005-2009 covers U.S. and Canadian models indicated.
Book Excerpt: 2005-2009 Jeep Grand Cherokee Repair Manual
GENERAL INFORMATION: ENGINE COOLING SYSTEM
All vehicles covered by this manual employ a pressurized engine cooling system with thermostatically controlled coolant circulation (see illustration).
An impeller-type water pump mounted on the front of the block pumps coolant through the engine. The coolant flows around each cylinder and toward the rear of the engine.
Cast-in coolant passages direct coolant around the intake and exhaust ports, near the spark plug areas and in close proximity to the exhaust valve guides.
Because of the design of the accessories, pulleys and drivebelts, some engines are equipped with reverse rotating water pumps, cooling fans and viscous fan clutches.
Always check with a parts department and install only componenets marked REVERSE on these components.
A wax-pellet type thermostat is located in a housing near the front of the engine. During warm up, the closed thermostat prevents coolant from circulating through the radiator.
As the engine nears normal operating temperature, the thermostat opens and allows hot coolant to travel through the radiator, where it's cooled before returning to the engine.
These systems incorporate a pressure cap on top of the radiator that raises the boiling point of the coolant. If the system pressure exceeds the cap pressure-relief value, the excess pressure in the system forces the spring-loaded valve inside the cap off its seat.
This allows either excess pressure or overheated coolant to escape through an overflow tube into a separate coolant reservoir.
TABLE of CONTENTS:
Introduction: About this manual | Introduction | Vehicle identification numbers | Maintenance techniques, tools and working facilities | Buying parts | Jacking and towing | Booster battery (jump) starting | Conversion factors | Automotive chemicals and lubricants | Safety first! | Troubleshooting
