Strange Noise from Air filter box - C200 W204
So i have an interesting problem. When i rev my car, i get this strange noise coming from the air filter box, almost as if there is a mini maize mill in there. The noise is even worse when i am driving and very noticeable at around 2-3000rpm. I am pretty sure people think i am driving a diesel car now. also feels like the engine is loosing torque, as in revs go up but "mr drive me" takes some time to pickup speed and shift gears up. So last night my brother and i removed the flexible pipe leading to the air filter intake and rev'ed the car between 2-4000rpms. That air filter box is racket really coming from the air intake system, and when i release the throttle, the thing seems to be blowing air out of the filter intake side.
a bit of history on this car. I hit a speed bump at around 100kmph sometime back, i managed to crack my TB pipe and the black hose leading EGR valve came loose. i drove the car some 200Ks with this problem before i could replace the TB pipe and hose. After this fix that's when the funny noise issue showed up.
does anyone know what the problem could be?