Cooling system fault finding (Peugeot 106)

Overheating

• Insufficient coolant in system ("Weekly Checks").
• Thermostat faulty (Chapter 3).
• Radiator core blocked, or grille restricted (Chapter 3).
• Electric cooling fan or thermoswitch faulty (Chapter 3).
• Pressure cap faulty (Chapter 3).
• Ignition timing incorrect/ignition system fault - petrol models (Chapters 1A and 5B).
• Inaccurate temperature gauge sender unit (Chapter 3).
• Airlock in cooling system (Chapter 1A or 1B).

Overcooling

• Thermostat faulty (Chapter 3).
• Inaccurate temperature gauge sender unit (Chapter 3).

External coolant leakage

• Deteriorated or damaged hoses or hose clips (Chapter 1A or 1B).
• Radiator core or heater matrix leaking (Chapter 3).
• Pressure cap faulty (Chapter 3).
• Water pump seal leaking (Chapter 3).
• Boiling due to overheating (Chapter 3).
• Core plug leaking (Chapter 2C).

Internal coolant leakage

• Leaking cylinder head gasket (Chapter 2A, 2B or 2C).
• Cracked cylinder head or cylinder bore (Chapter 2A, 2B or 2C).

Corrosion

• Infrequent draining and flushing (Chapter 1A or 1B).
• Incorrect coolant mixture or inappropriate coolant type ("Weekly checks").

Source of the article is posted at (peugeotbook.ru)