Engine model 518i produced since January 1993 (4-cylinder engine M40) (BMW 5 Series E34)

Since the M40 engine as a 4-cylinder engine has differences primarily in the removal of the timing belt and cylinder head, these works are highlighted here in a separate section. All other sections (Engine lubrication system, Cooling system, Ignition system and Fuel system) also apply to the M40 engine, produced since January 1993.

The new engine design, introduced in other BMW models in 1987, has one intake and one exhaust valve per cylinder. The camshaft, driven by a toothed belt, controls the valves via rocker arms supported by valve clearance compensators. The compensators ensure constant valve clearances, so that adjustments are not required. To increase the stability of the exhaust valves, they are filled with sodium.

Attention: Observe disposal regulations.

The lubrication system works with the so-called bicentric oil pump, located in the cover of the timing case and operating directly from the crankshaft.

Ignition and fuel injection are controlled by the Motronic system.