BMW M43B18 engine

In this article, we will consider the popular gasoline engine M43B18, mainly used for cars of the BMW concern, which belong to the 3rd and 5th series of production. Its working volume is 1.8 liters (to be more precise, then 1796 cubic centimeters). The power indicator is equal to 115 hp.

The M43B18 motor for BMW has an inline form and is a 4-cylinder motor. There are 2 valves on each cylinder (the total amount of valves is eight).

It is recommended to use 95 gasoline for good performance. It is almost impossible to accurately calculate fuel consumption, however, there are approximate figures. If you mainly deal with urban roads, then for 100 kilometers traveled you will take away in the region of 11 liters. The figure is not catastrophically large, but it also can not be called economical. If we are talking about moving on the highway outside populated areas, you will spend about 6 liters for the given segment of the path. However, in the case of a mixed driving style, everything is very good. The figure varies within 7-9 liters.

From the basic description of the motor, you can already draw some conclusions about its suitability for a particular driver. For example, if you want to buy a car that will allow you to be the fastest on the road, this is not your option. However, if you prefer to emphasize reliability, comfort and fuel economy, then this engine will definitely suit you. After all, if you carefully study the reviews of real owners, you will notice that the described unit fully corresponds to the above words.

M43B18 engine specifications

Advantages

The characteristics of the M43B18 engine are in general somewhat different from its direct ancestor, the M40B18, which the described motor succeeded in 1992. For example, there used to be twice as many cylinders (i.e. 8), and the crankshaft weighed more overall. But as far as the stroke is concerned, it hasn’t changed a bit. The pistons were also changed, and the compression ratio was increased to 9.7. Instead of a belt, the cylinder head now has a chain-driven timing system. This can be called a significant improvement, because you will have to think about replacing the chain after about 300,000 kilometers traveled. Hydrocompensators did not go anywhere, the valves became lightweight, the manufacturers decided to change the rockers. The motor was so good that it consistently served for about 10 years. This can be seen, including looking at the numerous positive reviews about the unit M43B18. In 2001, BMW cars got a new engine with the name N42B20 with a 2-liter working volume and generally more perfect characteristics.

Disadvantages

The motor manufacturers have tried so well that the M43B18 powertrain turned out to be practically without flaws, except for some not so essential trifles, which we will list further:

• Presence of extraneous noises. As a rule, it is expressed in tapping, crackling and so on. There may be several sources of the problem. First, it is the DISA damper, which tends to fail from time to time. Secondly, it is the hydrocompensators.
• Sometimes oil leaks. This is a very common problem with BMW engines, but it still needs to be addressed. How? First of all, look for the source of the leak. Mostly oil leaks from the valve cover. You need to replace the gaskets with sealant and the HVAC.
• Despite the fact that the described motor in general has significantly improved its performance compared to the M40B18, it also adopted some shortcomings of its “progenitor”. This is expressed in floating revolutions, periodic overheating, failures during acceleration and so on.
• If you consciously chose a car with the M43B18 engine, then this item is unnecessary for you. Still, the motor is quite weak. Its power figures may not be enough for some purposes that drivers may pursue.

If you have any problems with the engine, we strongly recommend that you contact the appropriate specialists who will help you deal with them. Self-treatment is not recommended, especially if you do not know such basic details as where to look up the BMW M43B18 engine number and so on.

Chip Tuning

Is there any point in trying to strengthen this unit? Probably not. After all, it does not have outstanding characteristics from the outset. It will be much easier to buy a more powerful motor. However, if you do decide to take this step, there are several ways to implement this plan. First, by purchasing a stocker with a head from M42, M44. Also additions in the form of 20-30 “horses” can be achieved by installing a cold intake, sporty launch manifold and camshaft with a phase of 266-272.

This engine is installed on the following models:

BMW 3-Series (E36)

BMW 5-Series (E34)