BMW's N43 petrol engine - did it have a reputation?

The four-cylinder naturally aspirated engine was produced by Bayerische Motoren Werke for 7 years. The unit was distinguished by a rather simple design, which, nevertheless, was quite expensive to maintain. The N43 engine got a bad rap for bad luck, but did it? To what extent the failures were caused by the design itself, and to what extent - the result of the negligence of the users themselves. We will try to answer. Read!

N43 engine - why did it replace N42, N46 and N45?

The N43 engine was developed to replace the N42, N46 and N45 engines. It should be noted that the new unit was not distributed in countries where high-sulfur fuel was used. For this reason, the production of N46 and N45 has not been discontinued. Were the units of measurement really different?

The new version was equipped with direct fuel injection. In 2011, as part of the use of new technologies in BMW engines, the N43 unit was replaced by a four-cylinder turbocharged version of the N13. 

What technical problems did users of the N43 engine have?

Among the most frequently mentioned breakdowns that occurred during the use of the unit, vehicle owners indicated:

• cracking of plastic timing chain guides;
• problems with injectors;
• malfunctions of the coil unit;
• damage to the NOx sensor.

N43 design - what you need to know?

It is worth mentioning the characteristics of the unit. The N43 engine was notable for its design, which was made from light alloys. In addition, the designers decided to equip it with start-stop technology - thanks to this, a car with this unit was supposed to become more environmentally friendly. All this was complemented by a system of energy recovery during braking.

Version N43B16 - key information

The unit in this version was to replace the N42B18. Both were based on the N43B20, but the newer engine was equipped with smaller cylinders - 82 mm, the N43B16 also had a shorter crankshaft with a stroke of 75,7 mm. Engine displacement has also been reduced to 1,6 liters.

In N43B16, the pistons had a higher compression ratio (12). At the same time, BMW designers decided to install direct injection, which entailed the removal of Valvetronic. This version of the engine was mainly used for BMW 16i models. In turn, the N43 was replaced in 13 by the N16B2011 - it was a 1,6-liter four-cylinder turbocharged engine. 

Version N43B16 - drive specification

This engine is a new 2 liter version of the N42B20 which has been produced with several modifications. This N43 engine uses the ia direct fuel injection system and the Valvetronic variable valve lift system has been removed.

The installation of new pistons was supposed to increase the compression ratio to 12. The whole thing is complemented by the use of a Siemens MSD 81.2 control unit. The N43B16 engine was replaced in 2011 by the N13B16 turbocharged unit. 

Breakdowns are the most common problems with the N43 engine

In both the first and second versions of the N43 engine, one of the most common problems that arise is the vibration of the unit. If such a malfunction occurs, the injectors will need to be replaced. Drivers of vehicles with this unit may also complain about uneven engine idling. The cause is usually faulty ignition coils. In this case, it will also be useful to replace the old components with new ones.

How to protect yourself from problems with this engine?

It also happens that the vacuum pump is leaking. This usually happens after a run of 60 to 000 kilometers. The effective solution is to replace the parts. When operating vehicles with an N43 engine, it is also important to regularly check the condition of the cooling system. This prevents it from overheating.

Anyone who has a car with this unit should also take care of the quality of the engine oil used. This is important because the operating temperature of the unit is usually high enough that the use of poor quality oil can lead to serious damage. 

The N43 engine can cause problems for many drivers, but with proper operation, you can use the engine without frequent expensive repairs by a mechanic. It is necessary to service the unit regularly and use good engine oil. With proper maintenance and periodic replacement of key components, a car with an N43 engine will serve its owner and avoid major problems.