Hey i have 2004 530d e60 with dpf and its driven 350 000 kilometer everything works fine but it has been making weird noise when idling about last 25 000 kilometers.

Noise sounds like something like drive belt would be ripped and slaps on somewhere. This noise only comes when engine is fully warm. Sometimes sound is regular and some days its irregular, sometimes its louder and sometimes quieter. Also if i increase revs few hundred rpm it goes away

https://youtu.be/GLGk5Kcu7EM here is link to a Similar case, car on the video sounds just like mine sounds (not my video)

I ve changed drive belt, pulleys, ac belt, belt tensioner and checked that vibration damper is looking good.

Any oil change or anything has no help for this sound.

Injector adjustments looks good and they are ok

I think sound is coming under intake manifold somewhere near oil temp converter or from front of the engine. Its pretty hard to locate this sound

Have anyone seen a Similar case and found the answer? ive heard from everywhere that this would be a normal sound of m57 and usual problem but to my ear it does not sound normal and I havent heard anyone to solve to this sound

Thank you for helping