1998 5.9 Grand Cherokee. Idling or reving engine sounds like all lifters not getting oil. typical lifter noise. Has oil pressure and have been driving for past eight years. Apparently has roller lifters? Is it valve train and if so does require complete lifters, cam, rockers? Have seen no bulletins. HELP!!!

 

You sure it's not an exhaust leak at the head/manifold?

 

definently not an exhaust leak. Sounds like you forgot to put oil in after oil changed.