Honda CB 600F Hornet 2007 Shop Manual page 216

COOLING SYSTEM
TROUBLESHOOTING
Engine temperature too high
• Faulty temperature gauge or ECT sensor
• Thermostat stuck closed
• Faulty radiator cap
• Insufficient coolant
• Passage blocked in radiator,hoses or water jacket
• Air in system
• Faulty cooling fan motor
• Faulty fan motor relay
• Faulty water pump
Engine temperature too low
• Faulty temperature gauge or ECT sensor
• Thermostat stuck open
• Faulty cooling fan motor relay
Coolant leak
• Faulty water pump mechanical seal
• Deteriorated O-rings
• Faulty radiator cap
• Damaged or deteriorated cylinder head gasket
• Loose hose connection or clamp
• Damaged or deteriorated hose
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