Problems of the radiator and fan: symptoms, cost and affected models
We have documented 4 faults of the radiator and fan in 4 cars. The most important by severity and frequency: fire risk from a short circuit in the radiator cooling fan (Opel Astra J), valeo radiator leak on the 5G-Tronic automatic gearbox with noise at low revs (Mercedes-Benz Clase C W203) and radiator fan controller capacitor that can fail (PG8BR campaign, 2018) (Nissan Qashqai II).
How it works and why it fails
Radiator and electric fan
The radiator dissipates heat from the engine coolant, helped by an electric fan that switches on when the temperature rises. Leaks from the plastic tanks, corrosion and failures of the fan or its control are its typical faults.
What to do
If the temperature gauge climbs in traffic or the fan does not run when the engine warms up, check it before the engine overheats. A coolant level that drops without visible leaks can be the radiator or, in the worst case, the head gasket.
General explanation by MotorFiable. The specific faults of each engine and car, with their sources, are on the linked pages.
Common symptoms
The symptoms that come up most often in the documented faults of the radiator and fan. Open each one to see what other faults cause it.
Problems of the radiator and fan by car
Faults documented on specific cars, which occur with any engine. From most to least important.
- 1Critical severityFrequency: OccasionalOpel Astra JFire risk from a short circuit in the radiator cooling fanYes: in 2014 Opel recalled around 60,000 Astra J/GTC cars from 2010-2012 because a deviation in the electrical design could cause a short circuit if the cooling fan seized, with a risk of fire.
- 2Medium severityFrequency: OccasionalMercedes-Benz Clase C W203Valeo radiator leak on the 5G-Tronic automatic gearbox with noise at low revsOn 5G-Tronic automatic gearboxes in units built up to September 2003, the Valeo radiator that cools the oil can lose its seal and produce a purring or rumbling noise at low revs when accelerating gently.
- 3High severityFrequency: RareNissan Qashqai IIRadiator fan controller capacitor that can fail (PG8BR campaign, 2018)Nissan issued a recall for Qashqais built between 6 June and 14 November 2018 because a ceramic capacitor in the radiator fan motor controller could fail, risking overheating and loss of engine torque while driving. The remedy is to replace the fan assembly.
- 4High severityFrequency: RareRenault Scénic IVCooling fan board capacitors that can crack (0D1C recall campaign, 2018)Renault recalled Scénic IVs built between 2 October and 12 November 2018 because capacitors on the electronic board of the cooling fan assembly could crack and overheat, with a risk of fan failure and fire.
Frequently asked questions
Which cars have problems of the radiator and fan?
Among those we have analysed: Opel Astra J (fire risk from a short circuit in the radiator cooling fan), Mercedes-Benz Clase C W203 (valeo radiator leak on the 5G-Tronic automatic gearbox with noise at low revs), Nissan Qashqai II (radiator fan controller capacitor that can fail (PG8BR campaign, 2018)) and Renault Scénic IV (cooling fan board capacitors that can crack (0D1C recall campaign, 2018)).
What symptoms does a fault of the radiator and fan cause?
The most frequently cited in the documented faults: overheating or temperature warning light, gearbox or clutch noise or rattle and gradual loss of power.