E36 m3 strange whooshing air in fluid noise behind wheel

[Nikaro]

Strange sucking whooshing noise like air in fluid being moved around a sealed system only when car is moving when stationary not there, under hard acceleration gets worse, does anybody have any ideas what this is? it doesn’t sound related to the steering pump, slowly getting more audible first noticed 4 or so years ago

[E-bmw]

OK, give us a clue.

Steering wheel, front left wheel, rear right wheel. etc. etc.

[Nikaro]

Problem sounds like fluid being pumped in a tube which is bit like a central heating when you can hear air in the radiators going through, worse on acceleration not apparent when stationary, engine revving not related to steering or road wheels, harder the acceleration louder the noise, sounds like it’s coming from behind the dash directly in front of driver
Air con? Thanks for your reply

[mmm-five]

Could your scuttle drains be blocked and holding water, which is then sloshing around as you drive?

[Nikaro]

No it’s clearly related to the engine thanks