Maintenance Schedule and Inspection Procedure for Porsche 968 Variocam Assembly
Part of content: The procedure does not include any necessary repair work that may be necessary as a result of the inspection findings. Variocam is a mechanism that allows the intake camshaft timing to be varied for different engine operating conditions, thereby maximizing torque. In the 968 engine, the exhaust camshaft is driven by a toothed rubber belt from the crankshaft. Earlier variants of Porsche’s 16 valve engines (2.5 liter 944S and 3.0 liter 944S2) used a similar setup but without the Variocam mechanism.
Instead, they used a simple spring and hydraulic operated chain tensioner whose purpose was simply to maintain constant chain tension. Possible Causes of Variocam Failure : Aging of the plastic pads (rails). With time and miles, the pads became much more brittle than when new, leading to an increased chance of breakage, and in any case to an increased rate of wear.
