The Mazda 1.6 B6 fuel injection tappet cover, often referred to as the valve cover or rocker cover, is the uppermost component of the engine’s cylinder head, enclosing and protecting the camshafts, rocker arms, and valve springs. For the B6 engine, particularly in its fuel-injected variants, this cover is typically made from cast aluminum or sometimes stamped steel. Its primary functions are to prevent oil leaks from the valvetrain area and to provide a mounting point for the positive crankcase ventilation (PCV) system, which manages crankcase pressures. A well-sealed tappet cover is crucial for maintaining proper engine lubrication and preventing oil contamination.
