Peugeot 407 Thermostats

The four key components are the radiator (which holds and cools the coolant), water pump (circulates coolant through the engine), thermostat (regulates coolant flow based on temperature), and cooling fan (draws air through the radiator). Additionally, Peugeot systems include an expansion tank, hoses, and sensors that work together to maintain engine temperature between 85-95°C. A complete radiator replacement typically costs R1,800-R4,500 depending on the model, while water pumps range from R800-R2,500.

Peugeot models, particularly those with EP6/THP engines (208, 308, 3008), can experience water pump failures due to timing belt integration, thermostat housing leaks, and expansion tank cracking over time. The 1.6 HDi/DV6 diesel engines may develop EGR cooler failures causing coolant contamination. South African heat and mineral-rich water can accelerate corrosion and scaling inside the system, making regular coolant flushes (R600-R1,200) essential preventative maintenance.

The most common symptom is engine temperature rising above normal, especially noticeable during traffic or hot weather driving in SA. Other warning signs include coolant loss requiring frequent top-ups, visible leaks creating puddles under the car, steam from the engine bay, or the heater not producing warm air. Ignoring these symptoms can lead to head gasket failure (R8,000-R15,000 repair) or complete engine seizure, so immediate inspection is critical.

The radiator holds most of the coolant and is the primary heat exchanger, with cooling fins dissipating heat as air passes through while driving. However, the entire system works together—the water pump circulates coolant through engine passages, the thermostat controls flow, and electric fans activate when additional cooling is needed. For Peugeot models, OEM radiators cost R2,200-R5,000 while aftermarket options start from R1,400, with installation adding R800-R1,500 labour.

Peugeot recommends coolant replacement every 3 years or 60,000km, whichever comes first, but South African conditions (high temperatures, dust, hard water) may warrant more frequent changes every 2 years or 40,000km. Always use approved coolant that meets Peugeot specifications for your specific engine type—mixing incompatible coolants can cause corrosion and blockages. A professional coolant flush and refill costs R600-R1,200 at most service centres and protects against expensive repairs.