Vibrating almost buzzing noise around 1500-2000 rpm?

[krice118]

This weird noise almost as if a metal piece is vibrating against another metal piece usually when engine is cold/just started and only happens while driving at low speeds and loves to start right around 1700-1900 rpm..... I recently installed a slightly louder flowmaster 40 muffler could that be why? Thanks

 

[brosama]

Where's the noise coming from? Underneath? Engine compartment? I think engine cover and heat shields are two of the most common vibrating noises on these.

 

[paflytyer]

The T-case lever will buzz/vibrate if there is something near it or left in the rubber boot portion.