Valve clearances of gasoline engines of the M52 series (BMW 7 Series E32)

The need to adjust the valve clearance on engines with 4 valves per cylinder has disappeared. Hydraulic tappets provide the required clearance each time the valve opens. Therefore, the valve mechanism operates without clearances, while ensuring a tight fit of the closed valves to their seats and, therefore, excellent compression. One of the advantages of hydraulic tappets can be appreciated by ear: a valve drive operating without clearances produces much less noise than a conventional one.

Caution: When the engine is started for the first time after the car has been parked for a long time, the hydraulic tappets may make a loud knocking noise; this effect occurs when all the oil has leaked out of the hydraulic tappets, causing gaps to appear in the valve drive again. There is no need to worry about this: the knocking will soon disappear and the valve drive will work silently again. If one of the hydraulic tappets continues to knock for a long time even after the engine has warmed up, it should be checked.

Install the cylinder head cover and intake manifold.