strang moaning sound
 

I have this moan/grind sound coming from what i thought was my getrag. The other day i took my hood stack off and put my old exhaust on for shits and giggles and the noise went away? I dont think it was the redicoulus loudness of the stack because you could feel it through the whole truck. any ideas what it could be? i was kinda wonderin if it had soemthin to do with the turbo and lack of backpresure with the Stack. Kinda stumped on what it was.

anyone?

my guess would be just the stack. if it went away when ya put the original exhaust back on and it quit, that would be my guess. good luck with it :tu: