noise on turning off

[Garthy]

hi, as i turn off my 20l d caddy i get a sort of high whoop noise. no lights on the dash and sounds smooth.

[Garthy]

i have just topped up with adblue and range on dash is 3000miles. how do i clear that too please

[Scoobysrt]

Ad blue should reset itself after a mile or two.

Your description of a whoop sound is a bit broad for me to guess.
Is it an induction sound, a mechanical sound, an exhaust sound for example?

It could be an injector shutting off or a noisy solenoid perhaps. A worn alternator bearing or idler pulley gives like a flat gazoo sound on turn off, is it like that?

[Garthy]

its a 19 plate.more like something slowing down. too k it to ac garage and its gone. hoping it is just a random noise

[Garthy]

the noise has just disappeared - done a few long runs but all good. maybe the very hot weather and aircon

[VAGdiagnose]

Maybe your flywheel?