Citroen DS4 Fan Clutches

They fail in two opposite directions. Seized open means the fan never drives, so the car overheats at idle and in traffic while behaving normally on the open road. Seized closed means the fan drives permanently, so you get a constant roar, worse fuel consumption and a slightly slower car. On the Relay and Dispatch diesel vans we see this around 150,000 km. The cold spin test tells you which: a healthy clutch offers noticeable resistance cold, a seized-open one spins like a bicycle wheel.

Roughly R340 to R1,300 depending on the vehicle and the brand, through our network. Before spending anything, confirm your vehicle actually has one — most modern Citroen passenger cars do not, and an owner chasing a fan clutch on an electric-fan car is looking for a part that was never fitted. Send the VIN and we will tell you in a minute which cooling system you are dealing with.

The answer splits by cooling system. On the older Relay, Dispatch and some HDi vans with a viscous clutch, a clutch seized open means the fan barely turns at idle and the temperature climbs the moment you stop moving. On the electric-fan cars, the same symptom points at the fan relay, the resistor pack, the temperature sensor or the fan motor — cheap parts, different diagnosis entirely. Identifying which system you have is step one, not step two.

The clutch has seized closed, so the fan is locked to the engine and spinning at full speed whenever the engine is running rather than only when cooling is needed. It is loud at every speed, and because you are driving a large fan continuously it costs a little fuel and a little power too. Mechanically it is safe — the engine is being over-cooled rather than under-cooled — so this one can wait for a workshop booking rather than a tow.

It depends which way it has failed, and the difference is important. Seized closed is noisy and thirsty but perfectly safe. Seized open means no cooling at a standstill, and you will overheat in Johannesburg traffic within a few kilometres. If you have to move a car with a seized-open clutch, do it at open-road speed where airflow through the radiator does the fan's job, avoid stopping, and go straight to a workshop.