C5 Aircross loud sound on cold engine

[marcinaldo]

Hello,

This is a long shot, but I'm getting desperate trying to find some information around this.

Since last month I had a problem with my C5 Aircross - there's a very loud, squealing sound that only occurs on cold engine when either idle or on reverse. It stops when as soon as I accelerate. I recorded this here because it is difficult to explain:

Currently, it does not happen at all when driving or when the engine was running. It usually occurs in the mornings.

It's like something I never heard from a car before. Citroen service checked it and they said it was because of worn out accessory belt drive, but they replaced it and the issue still happens. I'd like to ask for some guidance on what to potentially check before I get back there.

I also saw a post on reddit with exactly same issue: but it got no response.

I have the 1.6 petrol 180HP EAT8 engine and drive. If anyone has any idea about what could it be it would help me a lot.

Thanks a lot

[Fastbysuzuki]

Before I read all your post I thought accessory belt, then I read they had changed it, so other than checking the tension on that
Belt to make sure it has not come slack.
Stop the engine and see if the belt has come slack if so they did not tension it correctly.
Another thought is the water pump bearings starting to fail or alternator bearings

[routemaster1]

How old is the car? Is it still under warranty? If so I suggest a visit to the dealer.

[marcinaldo]

Before I read all your post I thought accessory belt, then I read they had changed it, so other than checking the tension on that
Belt to make sure it has not come slack.
Stop the engine and see if the belt has come slack if so they did not tension it correctly.
Another thought is the water pump bearings starting to fail or alternator bearings

Got it. Thanks for the suggestions. I'll check the belt first then.

How old is the car? Is it still under warranty? If so I suggest a visit to the dealer.

4 and a half years old. It's not under warranty anymore. I visited the official service and they replaced accessory belt. I will be scheduling another visit next week, but I also wanted to check if someone has experienced something like that. Thanks!

Edit: I asked on a French forum as well and somebody reported that they had the same issue and it is this part: https://www.ebay.fr/itm/134101765203 (not sure about the English name - valve rocker cover cylinder head?). Another person had the whole cover replaced so I'll follow up with the service on Monday and see what they say about this. Thanks again for all the suggestions.

[Handy Andy]

I also have the same issue. 1.6 petrol auto.
It has been back to the dealer several times. I have had the belt and tensioner changed, water pump checked, alternator checked. But the noise still occurs occasionally. Always on a cold engine but not ambient temperature related. I have learned to live with it. Still annoying though.

[Romania2024]

Hello, did you managed to find a solution? I have the same problem.

[Wayneh525]

I had the same thing... from my 2019 C5 Aircross 1.6 PureTech petrol. The local Citroen dealership had to contact Citroen in France, and they suggested to replace the Cylinder HeadCover (#C9818425480), which you will need a new gasket set (#C249G9).
It cost £ 481.70 from my dealership.

Noise has gone.
P.S. They changed the pulley belts first, but that did not stop the high-pitched whistling noise.