M40
The BMW M40 is a 4-cylinder engine, fitted to the 316 and 318 after 1987. It replaced the M10 as the standard 4-cylinder engine.
Contents
History
Versions
| Engine | Displacement | Power | Torque | Redline | Year |
|---|---|---|---|---|---|
| M40B16 | 1.6 L (1596 cc/97 in³) | 75 kW (101 hp) @ 5500 | 143 N·m (105 ft·lbf) @ 4250 | 6200 | 1988 |
| 73 kW (98 hp) @ 5500 | 141 N·m (104 ft·lbf) @ 4250 | 6200 | 1988 | ||
| M40B18 | 1.8 L (1796 cc/109 in³) | 85 kW (114 hp) @ 5500 | 165 N·m (122 ft·lbf) @ 4250 | 6200 | 1987 |
| 83 kW (111 hp) @ 5500 | 162 N·m (119 ft·lbf) @ 4250 | 6200 | 1987 |
M40B16
The M40B16 is a 1.6 L (1596cc) version of the M40 producing 102hp and 105 ft.lb of torque using Motronic 1.3 fuel injection.
The M40B16 was also fitted to the E36.
M40B18
The M40B18 is a 1.8 L (1796cc) version of the M40 producing 115hp and 122 lb.ft of torque. Like the M40B16, it also uses Motronic 1.3 fuel injection
The M40B18 was also fitted to the E34 from 1988 to 1994, and briefly the E32 in 1992-1993.
Characteristics
Engine Bay
Servicing
Main article: Basic M40 Servicing
Every engine needs its fluids and filters changed regularly. The M40 engine also needs its timing belt replaced at regular intervals. Learn more about changing the timing belt.
Common Problems
Won't Rev Over 5000
Unfortunately, this is a common sign of engine wear, and indicates a worn out cam shaft. The problem can be diagnosed in two ways. If the engine sound can be described as "sounding like a skeleton wanking in a dustbin" then your cam is very likely worn.
To confirm, remove the rocker cover and baffle plate so that you have access to the cam shaft, and run your finger nail over the cam lobes. If you can feel scatches, grooves or other imperfections, the cam is in bad condition.
The only solution is to replace.
