Cooling system malfunctions

Overheating

• Insufficient amount of coolant in the system (Section 1).
• Faulty thermostat (Section 3).
• Radiator fins blocked or grille blocked (Section 1 or 3).
• Faulty electric fan or thermal switch (Section 3).
• Radiator cap damaged (Section 1).
• Coolant pump drive belt worn or incorrectly tensioned (Section 1).
• Incorrect ignition timing (Section 1).
• Inaccurate coolant temperature gauge sensor (Section 3).
• Air lock in the cooling system (Section 1).

Hypothermia

• Faulty thermostat (Section 3).
• Inaccurate coolant temperature gauge sensor (Section 3).

External coolant leak

• Damaged or loose hoses (Section 1).
• Leak from radiator core or heater matrix (Section 1 or 3).
• Radiator cap damaged (Section 1).
• Leakage at coolant pump seal (Section 3).
• Boiling due to overheating (Section 3).
• Leakage through the plugs in the cylinder block (Section 2).

Internal coolant leak

• Leakage through the cylinder head gasket (Section 2).
• Cracked cylinder head or cylinder bore (Section 2).

Corrosion

• Infrequent draining of fluid and flushing of the system (Section 1).
• Wrong type of antifreeze used (Section 1).