So my L494 has developed a very soft tapping noise when accelerating, I originally thought it will be the engine but after inspecting the engine and listening whilst driving I can only hear it from inside the cabin and it sort of coming from behind the dash screen area. Its a very light tap/flap noise that increases with acceleration but then peters out once your past 2000rpm. You can only hear it with the radio and fan off.

Any ideas what it could be thats not engine related. Both manifolds were swapped earlier in the year also so I dont think its a manifold noise and I've had no errors on screen.

In my year of ownership I’ve come to realise where a noise sounds like it’s coming from can be quite deceiving. At first my rear differential noise sounded like it was coming from under the centre console. I first thought it was my transfer case.

Might be worth having a look underneath, check your front and rear propshafts and the rest of the running gear in that area.

Hi Karl did you get to the bottom of this.
Thanks Bobby

Yes actually turned out to a bad injector!
Got worse over time and when the engine got upto temp.
Swapped with a new injector all fine

Thanks so much how did you determine which injector it was. Thanks

When you take the 2 sound deadening covers off either side of the engine you will see vapour from the diesel or simply put your finger on it and you will feel the injector not in time with the engine.