Kad44p

[Johnnyeff]

Sounds like exhaust is leaking in engine bay.Air filter is thick black and only 3 months old. When i switched off engine sounds like air is leaking from somewhere for about 30 seconds.

 

[spannerman]

The noise is the exhaust downpipe filling up with water until it matches the level outside. I would look at the exhaust bend where it clamps to the turbo and also the rubber muff on the downpipe.