Hey I have a 92 Z24 that when I first start it. The engine makes a high pitched tapping sound almost like a knock but I sounds more like a piston slap or wristpin slap. Does anyone know what I can do to make that noise lessen or go away cheaply without boaring out the cylinder. I change my oil on time everytime. I think it is coming from the bottom of the engine on the passenger side. If anyone can help I would appreciate it.