Timing Chain

Fig 1: Timing Chain

Courtesy of BMW OF NORTH AMERICA, INC.

There is a fixed chain guide on the intake side of the engine. The exhaust side has a semi-floating guide that is spring-loaded and contains a self-ratcheting tensioner to retain the adjusted position. Engine oil pressure fine-tunes the free play using a hydraulic tensioner.

Fig 2: Crankshaft Gear Timing Marks

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 3: Camshaft Gear Timing Mark

Courtesy of BMW OF NORTH AMERICA, INC.

The timing chain incorporates three copper color links that are used to assist timing chain installation. Both the crankshaft and camshaft gears incorporate timing marks, which are used in conjunction with the copper coated chain links.