If the vehicle?s engine experienced a serious mechanical problem, it is possible that small pieces of metal debris resulting from the mechanical problem may have become deposited in the intake manifold, air intake hoses, exhaust manifolds, exhaust down-pipes, turbocharger, supercharger, and/or intercooler. If these pieces are not removed prior to the installation and operation of the replacement engine, the pieces may be drawn into the combustion chamber, which can cause a knocking noise and subsequent serious engine damage.
