Hi all,

I have a 08 E320 with 160k miles with all service up to date. When I first bought the car until about 5k miles ago, the engine has been really quiet for a diesel. lately, I'm noticing that the engine noise is getting louder. It's starting to really sound like an older diesel engine.

I noticed it at both idling and accelerating. It's just a little bit louder than usual at idle, but when I accelerate, it really sounds like an older diesel engine, much louder than before.

The car still runs great, no codes or anything.

Does anyone have any idea what could be causing this?

Thanks in advance for all your help.