Flapping noise at the front - aircon related?

[Robbie1974]

Hi all, I've read many posts around noisy Air Conditioning with the MG4 when it is turned on, in my X-Power I have the reverse of this. Drive the car and as speed increases a loud flapping noise begins, like a loose air vent cover or alike in the bonnet area. This continues if I turn on the blowers, however if the air conditioning is switched on it stops immediately. Assumption is it's something to do with the aircon given this but so far the dealer can't find the cause.
This is a really loud noise, there is no mistaking it by anyone in the car. Interested if anyone else is or has experienced this. Posts i've read discuss noise when aircon is turned on, this is certainly the opposite. Thanks all.

X-power/R63/6k miles/2024

 

[Ian Key]

The chances are it's the front vents below the bumper. Without the AC on they are closed and if they have a weak return spring it could be the air pressure "flapping" the vents. When you turn the AC on the vents open allowing the air to flow uninhibited.

 

[Robbie1974]

The chances are it's the front vents below the bumper. Without the AC on they are closed and if they have a weak return spring it could be the air pressure "flapping" the vents. When you turn the AC on the vents open allowing the air to flow uninhibited.

Thank you for this Ian, it makes perfect sense especially as the flapping noise alters whilst say driving on the motorway opposed to a backroad with many turns. We (dealer and I) have concentrated around the aircon and the general blowers. I'll take this direction and see if this resolves, will feedback. Many thanks

 

[OriginalBigAl]

Its possible a plastic bag or similar might be wrapped in the vents and disappears from sight when they close.

 

[mg4mc]

Or the undertray flapping with the different airflow with vents open vs closed.

 

[Slipstream]

Its possible a plastic bag or similar might be wrapped in the vents and disappears from sight when they close.

That's what I was thinking

 

[Robbie1974]

Thank you for the thoughts on this. I've now checked for anything obvious with the vents open - all clear. The under tray seems to be firm, no movement. I've booked the car back into the dealer for them to look at the return spring view.