BMW M43 SOHC Straight-4 Engine

The BMW M43 is a straight-4 SOHC piston engine which replaced the M40 and was produced from 1991-2002. Displacement ranges from 1.6 L to 1.9 L. The M43 powered base-model cars, while higher performance models at the time were powered by the DOHC M42 (and its M44 successor).

A variant using natural-gas was produced for the E36 318g and the E34 518g.

Compared with its M40 predecessor, it features a dual length intake manifold (called "DISA" by BMW) to provide torque across a wider rev range, knock sensing and a timing chain (instead of the M40's timing belt).

The M43 was produced at the Steyr engine plant. A total of 1,204,734 units were produced.

In 1998 the displacement was increased to 1.9 litres, increasing torque to 180 Nm at 3900 rpm.

Models

M43B16

The 1.6 L (1596cc) M43B16 produces 102 hp and 150 Nm. It uses the Bosch Motronic 1.7.1 fuel injection system.

Applications:

• 1993-1999 E36 316i
• 1994-1998 E36 316i Compact
• 1998-2002 E46 316i

M43B18

The M43B18 has a 1796 cc displacement. It produces 115 hp and 168 Nm and uses the Bosch Motronic 1.7.1 fuel injection system.

Applications:

• 1992-1998 E36 318i
• 1994-1996 E34 518i
• 1995-2001 E36 Z3 1.8

M43B19

The M43B19 (also known as the "M43TÜ") is the largest M43 engine, with a displacement of 1895 cc. It produces up to 118 hp and 180 Nm and uses BMW BMS 46 fuel injection system.

Applications:

• 87 kW (118 hp) and 180 N·m (133 lb·ft)
  • 1998-2001 E46 318i/318Ci
  • 2001-2003 BMW E36 Z3 1.9
• 77 kW (105 hp) and 165 N·m (122 lb·ft)
  • 1999-2001 E36 316i compact
  • 1999-2004 E46 316i