Peugeot 308 - Cooling fan cuts in/out constantly

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Sat 30 Nov 2024 10:09
Peugeot 308 - Cooling fan cuts in/out constantly - Lll95

Hi, I have a 2017 Peugeot 308 1.2 on 154k.

As soon as I start the car up, the cooling fan will cut in for a few seconds, go off for a few seconds, and repeat this the entire time the engine is running, regardless of engine temperature. The fan cuts in and out the entire time the engine is running.

Also, about 1 in 5 times I switch off the engine, the cooling fan will start up and won't stop. It does this seemingly at random, and engine temperature has no effect on whether or not it does this. However, if I restart the engine and switch it off again, the fan stops. I have to do this approximately 1 in 5 times I switch off the car.

My first thought was the coolant temperature sensor, however the temperature gauge seems to be accurate and rises as you would expect.

I was wondering if anyone has any ideas or experiences of this before I start throwing parts at it!

Thanks in advance!

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Sat 30 Nov 2024 10:22
Peugeot 308 - Cooling fan cuts in/out constantly - elekie&a/c doctor
On many later Peugeot models , the cooling fan is cycled when the engine management system detects a fault. You’ll need some diagnostic testing to find out what’s going on.
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Sat 30 Nov 2024 14:30
Peugeot 308 - Cooling fan cuts in/out constantly - Chris M

"I have a 2017 Peugeot 308 1.2 on 154k"

Music to John F's ears.

Please tell us you have had nothing but trouble with this engine. Many on here will be shocked that a Puretech engine could reach 54k miles let alone 154k.

There are one or two that would probably go as far as saying you're a liar :)

Edited by Chris M on 30/11/2024 at 14:32

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Wed 11 Dec 2024 18:55
Peugeot 308 - Cooling fan cuts in/out constantly - Lll95

Without trying to tempt fate, mine's been excellent. Runs faultlessly despite the mileage and doesn't use a drop of oil. I had the wet belt replaced earlier this year and it was nowhere near as expensive a job as I feared. Well worth getting it done for peace of mind alone as I think it was still on the original belt!

This cooling fan thing is the only issue I've had with it and at least the car remains fully functional in the meantime.

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Sun 1 Dec 2024 00:12
Peugeot 308 - Cooling fan cuts in/out constantly - edlithgow
On many later Peugeot models , the cooling fan is cycled when the engine management system detects a fault. You’ll need some diagnostic testing to find out what’s going on.

Instead of the dreaded "Check Engine Light"?

Hmm...(French) logic?

I suppose it MIGHT mean that you could still pass an MOT, in which case, Vive La Difference.

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Mon 2 Dec 2024 12:35
Peugeot 308 - Cooling fan cuts in/out constantly - Gibbo_Wirral

I'm not certain, but I think there's more than one coolant sensor on the car - one which relays info to the dashboard and an "internal" one for the ECU

Getting some live data read with Diagbox might shed more light on the situation.

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Wed 11 Dec 2024 18:50
Peugeot 308 - Cooling fan cuts in/out constantly - Lll95

Thanks. Been a hectic couple of weeks but will look into this when I get a chance.

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Wed 11 Dec 2024 18:50
Peugeot 308 - Cooling fan cuts in/out constantly - Lll95

Thanks. No warning lights or stored codes.

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Thu 12 Dec 2024 13:07
Peugeot 308 - Cooling fan cuts in/out constantly - Gibbo_Wirral

How's the live data looking with Diagbox, particularly air, fuel and coolant temps?

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Sun 29 Dec 2024 20:47
Peugeot 308 - Cooling fan cuts in/out constantly - Micky-BO

the cooling fan has to be controlled so that allows the engine to maintains a constant tempature

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