Have you tried the old "screwdriver to the ear" trick? You can get real close to the origin of the noise thataway. If it is piston noise you can even tell which piston it is. A grateful friend saw me doing just that to his ride and when repaired he brought me an electronic ear with a metal rod on it. Man it is nice to put those earphones on and not have to lean into a running engine.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist