I have been subject to a weird noise. Usually seems to occur when the car is warmed up but can be random. Seems to be coming from behind the back of the engine I have used a bar to listen to the alternator plenum head and block and it just seems to be resonating from down below the plenum. It sounds a bit like a cow bell or heat shield revirbirating against something.
Its the higher pitch noise its hard to pick up so much on the video, its a quiet engine on this one but these phones pick up everything. See what people think?! If you turn it off and on a few times it goes.