so I have a 2014 C250 and had timing chain and both camshaft adjusters and tensioners replaced back in June , went to get the car and still had rattle noise , kept taking it back to the dealership and they kept telling me they couldn't hear anything. Finally check engine light came on stating exhaust camshaft over advanced bank one , they checked it out told me it was a stored code that all of that had been replaced, noise kept getting worse, hear he noise between 1500 to 2000 rpms. Then had a mechanic ride with me to hear the noise and after a day they said the noise was coming from the camshaft adjusters so they just replaced both again and I went this Friday to get the car and guess what , noise still there and even louder . Like what is going on with this repair and why can't they get it fixed .. so stressed..