2011 E63 AMG 6.3l Whistle from inside intake manifold
1- Leaking intake manifold
2- Leaking throttle plate inside manifold
3- Leaking intake manifold gaskets
4- PCV problem
If you are to replace the PCV replace the manifold gaskets at the same time and vice versa.
all of these are common issues for the M156 engine.
Good luck




