Ok had a tap so I changed the LIM gasket and lifters (tap still there) sounds like it's definately valvetrain, any ideas? Not a total waste of time got the updated gaskets and new lifters! Also under normal driving conditions the car drives fine Great! in fact but when I step it down accelerates normally till about 4000 rpms then it seems to surge power on and off like the fuel pressure is fluctuating. Any suggestions? No SES light and no missfires. like I said car performs great normally but I HATE that tap and accelleration issue it is really annoying. Appreciate your time and thaughts just wondered if any1 had these same experiences. Thanks!