My 2005 Forester XT w/5speed has a ticking sound that occurs, sync’d w/RPM, ONLY when the air intake is below 40 degrees. I does not go away until air intake is over 45 degrees. I cannot find it by listening with the hood up or stethascope, heard best from the inside-passenger side. The engine was replace by Suby at 40,000 (now 125000) when they Dist Rep said it was a slapping piston. It was not and ticking continues. ANYONE?? Anyone?..Bueller?