Haven't seen anything quite like this here before.

Low loud growl, sometimes "pop" on hard acceleration. Not pinging - much louder and lower.

04SE

Any ideas?

 

265 horses?

 

Yeah, that, too. Seriously, though, it suddenly got much louder than normal engine noise, and the corresponding vibration is pronounced. Stops after a few seconds.

 

Problem solved. Bent exhaust shield (where it makes a right angle turn at the bottom -- hit on something...) Hard to believe this could make so much noise, but after bending away from pipe, noise went away. New part ($65) on order.