Hey I have been having this weird sound from my exhaust. Sometimes when I give it a small rev to like 3 grand it will make like a grind sound. Even when Im driving and then shift to the next gear it will do the same thing.... But usually only around 3 or 4 grand. I do not have a clue what the H*ll it is. It just recently started happening. I haven't done anything different. ANYONE ???????????

 

loose connection maybe?