Cooling system (Opel Omega A)

Overheat

• Not enough coolant in the system
• Thermostat is faulty
• The radiator core is clogged
• Cooling fan or thermoviscous coupling is faulty
• Temperature sensor/indicator gives incorrect readings
• Air lock in the cooling system
• The expansion tank cap is damaged

Hypothermia

• Thermostat is faulty
• Temperature sensor/indicator gives incorrect readings
• The thermoviscous coupling is faulty

External coolant leak

• Hoses or their fastening clamps are worn or damaged
• The radiator core or heater matrix is leaking
• The expansion tank cap is damaged
• The internal seal of the cooling pump is leaking
• The gasket between the cooling pump and the cylinder block is leaking
• Boiling due to overheating
• The cooling jacket plug is leaking

Internal coolant leak

• The cylinder head gasket is leaking
• Cracked cylinder head or cylinder block

Corrosion

• Rare fluid replacement and system flushing
• Incorrect coolant mixture ratio or incorrect coolant type