Fan Coming On.

[Pete112944]

Hi, I have 2009 C5. I recently bought it and the cooling fan comes on intermittently. The temperature is showing normal and the engine is not overheating. I have been told that it needs a sensor replacing. If this is so, is it a big job. Thanks

[paul.h]

Welcome to the forum.

 

There may be nothing wrong with the car. You need to plug in a code reader that gives live engine data to see what temperature the coolant sensor is giving to see if it is normal. Should be ambient temperature before starting the car in the morning and then around 90 to 96°C once warmed up. The fan should cut in about 96°C but also it should run if the air con is on. Faulty sensors tend to go to max temp soon after starting the engine.

[Pete112944]

Thanks for that, I will get it checked.

[MikeLane]

Sometimes on a hot day or after a "hard" run, the fan will stay on after the ignition is turned off and the car locked.

[Pete112944]

Yes, I realise that, this fan is coming on intermittently, sometimes when the engine is cold and I turn on ignition,it will run for a few seconds, or it will stop and start at will