As mentioned in the title I am experiencing a perplexing burbling sound that can be heard from the air filter box when the car is revved at idle.
The noise only occurs once the car has fully warmed up.
Noise can be heard both inside and outside as shown in these clips.
Disconnecting the intake manifold hose only makes the noise get louder.
I have a long journey ahead of me at the end of this month and I am extremely perplexed as to what the noise is, very worried.
Any help with this would be greatly appreciated.
Side note: I will be swapping out the manifold flaps for new ones later this month.