My MK5 makes a strange flapping sound at around 40-50mph and gets faster as I speed up. Sounds like somethings is loose but I cant pinpoint it because I pretty much concentrate on driving at those speeds! And it doesn't happen at lower speeds. any known issues? Thanks.

could be any number of things you really need to get a passenger.

Grab some willing family membor or a friend to sit in the back of the car and to listen and agree they can hear the noise.

Then you or they need to point in the direction on where it is coming from.

A Rattling Wheel cover

(Rattling) or Loose fan/drive belt tensioner

Check the wheelnuts are tight.

Ascertain if it is coming from the engine by sitting in your car on the drive with the window open and slowly increase the revs up to about 3000-3500 to see if it is the engine.

Jamie

Sounds like it could be a loose wheel-arch liner perhaps.

Hi FreqFace, did you ever find the cause of the flapping sound?

Today I noticed a flapping sound coming from the rear driver’s side wheel.area of my Mk5 Fiesta - while driving with the window down!

I can hear it at low speed and it speeds up with the speed of the car.

 

 

3 minutes ago, Merval said:

Today I noticed a flapping sound coming from the rear driver’s side wheel.area of my Mk5 Fiesta - while driving with the window down!

See if all the plastic clips are still in place that holds the inner plastic arch, i'd physically grab hold of anything that might move, see if it does move. 

1 hour ago, Ian Lanc said:

See if all the plastic clips are still in place ...

Good to give an answer to a 15 year old thread, hey, David Cameron was PM back then, heady days 🤣

38 minutes ago, StephenFord said:

Good to give an answer to a 15 year old thread, hey, David Cameron was PM back then, heady days 🤣

Ahh, somehow I read the original post as March 25, when the charismatic Gordon Brown was still PM.

1 hour ago, Ian Lanc said:

See if all the plastic clips are still in place that holds the inner plastic arch, i'd physically grab hold of anything that might move, see if it does move. 

Thanks for the tip, I’ll try that tomorrow.

15 hours ago, StephenFord said:

Good to give an answer to a 15 year old thread, hey, David Cameron was PM back then, heady days 🤣

Erm! Stephen I was replying to the post from 16 hours ago, get on the naughty step will you 

 

Is the ventilator on the roof going round ?  Sorry, I think they were only fitted on vans!

So the flapping sound was gone the next day!

My guess is something got attached somewhere behind the rear wheel and eventually worked itself loose.

On 7/20/2025 at 6:13 PM, Paulkp said:

Is the ventilator on the roof going round ?  Sorry, I think they were only fitted on vans!

Perhaps I should explain my corny sense of humour......

About 50 years ago, our handyman got a new van, and it was soon after, he complained about a flapping sound, so the engineers had a look, and did not find a thing.  Still complaining, so van was taken for a drive with somebody in the back, and it was found to be the rotating ventilator on the roof !

 

13 minutes ago, Paulkp said:

Perhaps I should explain my corny sense of humour......

A few years back, I installed a DAB MagMount aerial on the roof of my car. After, I heard the most annoying whistling noise which I quickly tracked down to the new aerial. A few positioning adjustments (twisting and location change) soon sorted it...