1.4 litre petrol engine with 55/74 kW (75/100 hp) (VW Polo 4)

The 4-cylinder petrol engine AUA/BBY/AUB/BBZ with a working volume of 1.4 l has a cylinder block and cylinder head made of aluminum alloy. The camshafts located in the crankcase above the cylinder head drive four valves above each cylinder via pressure levers with rollers. The pressure levers are fixed at one end to hydraulic support elements, which eliminate gaps in the drive of the corresponding valves. Thanks to the needle bearings in the rollers of the pressure levers, the stroke of the cams is transmitted to the valve stems with minimal friction losses. The camshafts are driven from the crankshaft using a toothed belt.

The aluminum alloy cylinder block has cylinder liners cast from gray cast iron. The crankshaft is mounted in the cylinder block on five main bearings. Do not loosen the bearing cap mounting bolts, otherwise the cylinder block and crankshaft will need to be replaced as a set. The coolant pump is mounted on the cylinder block at the front and is driven by a toothed belt. The oil pump gear is driven via a cam pin from the crankshaft.

[The original text can be found at: VWManual]