I dont know what it is, but it sounds kinda like a pully or something is taking a crap on me. I got into some deep water at spring creek and now it sounds kinda like a shhhhhhhhhhhh and rattle sound. I checked for a plate rattling or something and checked the air filter and such for water, nothing. All looks well but it is pretty noticeable to me and kinda alarms me. Guess the dealer is next. Anyone have something like this happen?