BMW M40B16 Engine

  1. Specifications
  2. Overview, problems
  3. Performance tuning

M40B16 Specs

Manufacturer Steyr Plant
Also called BMW M40
Production 1988-1994
Cylinder block alloy Cast iron
Configuration Straight-4
Valvetrain SOHC
2 valves per cylinder
Piston stroke, mm (inch) 72 (2.83)
Cylinder bore, mm (inch) 84 (3.3)
Compression ratio 9
Displacement 1596 cc (97.4 cu in)
Power output 73 kW (100 HP) at 5,500 rpm (E36)
75 kW (102 HP) at 5,500 rpm (E30)
Torque output 141 Nm (104 lb·ft) at 4,250 rpm (E36)
143 Nm (105 lb·ft) at 4,250 rpm (E30)
Redline 6,200 rpm
HP per liter 62.7
Fuel type Gasoline
Fuel system Bosch Motronic 1.3 (E30)
Bosch Motronic 1.7 (E36)
Weight, kg (lbs) ~132 (290)
Fuel consumption, L/100 km (mpg)

for E36 316i
10.2 (23.1)
6.1 (38.6)

7.5 (31.4)
Turbocharger Naturally aspirated
Oil consumption , L/1000 km
(qt. per miles)
up to 1.0
(1 qt. per 750 miles)
Recommended engine oil 0W-30
Engine oil capacity, L (qt.) 4.0 (4.2)
Oil change interval, km (miles) 7,000-10,000
Normal engine operating temperature, °C (F) 90-95 (195-203)
Engine lifespan, km (miles)
-Official information

300+ (185)
Tuning, HP
-Max HP
-No life span loss


The engine is installed in BMW 316i E30
BMW 316i E36

BMW M40B16 engine reliability, problems and repair

This 4-cylinder straight engine belongs to BMW M40 series. It was firstly introduced in 1988 and developed on base of M40B18. The difference between M40B18 and M40B16 includes crankshaft with less stroke (it was 81 mm) and modified pistons. Connecting rods are the same. Their length is 140 mm. At the same time engine has new intake manifold, throttle body, spark plugs and ECU.
Cylinder head is also the same. It consists of 8 valves and one camshaft (SOHC) with hydraulic tappets. Diameter of inlet valves is 42 mm while exhaust valves are 36 mm in diameter. Specifications of camshaft are as follows: duration 244/244 deg, lift 10.6/10.6 mm.
Engine is equipped with timing belt. However the belt itself is not very reliable. At the same time it is not wide enough. It results in low lifespan and durability. In average timing belt and roller replacement is necessary after every 25 000 miles (40 000 km) of mileage when it comes to M40B16. If it is not done, belt break down can result in bended valves.
This engine was mainly used for BMW 16i models.
M43B16 appeared in 1993 as alternative to the previous engine version. M40B16 was totally replaced by new motor within two years.

BMW M40 engine modifications and differences

1. M40B16 (1988 – 1991) is a base modification of engine without catalyst. It has 102 HP at 5,500 rpm, 143 Nm of torque at 4,250 rpm.
2. M40B16 (1991 – 1994) is a new version of engine with catalyst. It has 100 HP at 5,500 rpm, 141 Nm of torque at 4,250 rpm.

BMW M40B16 disadvantages and problems

Possible malfunction of M40B16 are actually the same as common problems of M40B18. HERE you can learn more about possible problems and disadvantages.

BMW M40 engine tuning

M40B16 Stroker. M40B16 to M40B18

It should be noted that M40 engine tuning is not the best solution for investment. It would be better to buy more reliable and powerful engines such as BMW M50B25 or M54B30, proceed with swap and enjoy fast ride.
If you still want to develop your small M40 motor than you should forget about chip-tuning as it will be absolutely useless in this occasion. Stroker is the best variant for this engine.
The first step is to remake your M40B16 to M40B18. You will need stroker kit for this mode taken from M40B18. The kit includes crankshaft, pistons, throttle body, intake manifold and ECU.

M40B16 to M40B21

If you need to increase the rate of engine displacement up to 2.1 liters, you need to buy crankshaft from M47D20 with 88 mm stroke. At the same time you need to increase diameter of cylinders up to 86 and purchase BMW S50B30 pistons with groove and connecting rods.
In addition you will also need several details from BMW M42 which include timing chain kit, intake and exhaust system, ignition coils, ECU and cylinder head. After everything is assembled it will provide your motor with additional 50-60 HP.
Turbocharged M40 is even more ridiculous and expensive thing. Only stock cylinder block will be left. At the same time you will get not enough power and absence of reliability in the end.

M40B16 Turbo

Due to the fact that M40B16 is actually equal to M40B18, tuning of both motors is also the same. HERE you can learn more about M40B16 turbocharge tuning.