I was sitting at a stop light and noticed a loud knocking coming from my engine, no check engine lights on at all.. seems to run great.. not missing.. it sux because i have an ear infection in both ears right now and cant figure out the sound...it did die on me once.. when i went to restart it didnt wanna turn over at all.. so i had it towed home went out this morning hit the key and it took right off... still a knocking sound.. i started tearing into the engine today pulled the back valve cover and everything seems tight... im gonna go pull of the timing cover and check the chain.. if it good im out ideas other than a rebuild... any ideas would be apreciated 