Mine is kinda noisy as well. I personally think it is a combination of things. For one the valvetrain and second the exhaust manifolds. Mercedes uses stainless steel which is kinda thin so the sound from the exhaust pulses are quite noticeable. I'm actually waiting for Floored Fab in Arizona to complete the shorty headers. They are going to be mild steel with Jet Hot coating. I'm hoping that these headers will both eliminate some noise and make a more tuned exhaust note. Plus I'm always up for a little more horses too.