BMW N20 and N26 Four Cylinder Turbocharged Engines



In the year 2011/12, BMW introduced a radical change in that they swapped their well-loved straight 6 engine with a variety of turbos with four cylinders. This was driven by ever-stricter emission laws as well as the need to improve fuel efficiency. It’s still a controversial choice and the only model available was one of them, the 3.0 turbo N55.

In its first version in 2011, the BMW N20 was offered as a 320i 2.0 turbo as well as its version 328i 2.0 with a larger turbo. Traditionalists, like myself weren’t overly amazed by the latter. There’s not much of a difference in price between the two models since there’s little difference in engineering. Some of the reasons why buyers go for the more affordable variant in UK include a lower annual road tax because of less emissions, lower coverage, better economics, and corporate car tax.

In 2013, a 1600cc version was in development to drive the F10 520i. As of the time of writing, all other models utilize the N20 with two liters, however there are a variety of options of tuning for the various Z4, Three, X1, and one series.

Power figures must take a pinch of salt, or three times more, particularly for used vehicles. The efficiency of the engine and turbo is contingent on how it’s been taken care of and used. If the engine has accumulated a lot of carbon deposits on the rear of the valves, power is likely to be reduced a amount. In any of the turbo engines, there’s a variations in the condition of tune compared to the factory as well as differences between local markets. Additionally, a significant amount of owners will have their cars rebuilt to increase output.

The N26 was designed for the markets that required a super low emission N20. It comes with features like fuel pipes made of all-metal instead of rubber and engine sensors that are added.


In many ways, the BMW N20 is about two thirds of the six-cylinder N55. The current BMW idea is to create three 6 and 4-cylinder BMW N20 engines, each with 500cc of capacity per cylinder. This is the area where the N20 is located. BMW think that cars less than 1300kg should come with the three-cylinder N13 which is that is the BMW N20 as well for the larger or high-performance models, the six.

The turbo is twin scroll, this is the reason you’ll notice “Twin Power” on the engine’s cover for the acoustic. Twin scroll turbos feature two inlets and nozzles. There is a smaller sharply angled one that allows for quick response, which reduces the turbo’s lag, and a larger smaller angled one that is designed for more boost production. This is similar to what they did with the turbos with variable incidence. Two exhausts from cylinders are fed into each turbo nozzle section.

Read also:BMW N20 Campaire With BMW B48

As you’d expect , the engine’s Valvetronic and has double VANOS. It is powered by Bosch Direct Gas Injection (GDI) as well as a high-pressure (200 bars) fuel pump, which is driven by an exhaust camshaft. It features an automatic stop and start as well as an electric coolant pump that is part of BMW’s Efficient Dynamics measures.

The block is made of aluminium and features iron cylinder liners that are made with the thin film deposition technique. The engine is equipped with a sturdy cast crankshaft that is forged and has the four weights for balance. To reduce friction in the piston, the central line of the crankshaft’s shaft is offset from the cylinders that are above it, which is a first for BMW. The engine is equipped with twin balancer shafts for reducing vibration. This is a technique that was developed by M43TU. M43TU engine.

Initially, the N43 BMW was having issues with direct injectors as well as ignition coils that failed early due to heat. To prevent this, the N20 included extra cooling passages close to the injectors. The engine was equipped with a brand new design for the crankcase ventilation system which was an integral part of the valve cover. Perhaps it’ll be less clogged.


Since it is a direct-injection engine, the intake valves won’t be being cleaned by fuel. They’ll accumulate carbon deposits, which must be cleared by removing the intake manifold every 40 000 miles. All GDI engines have this problem and not only BMWs as it’s the cost we pay to get reduced emissions. It’s more prevalent for engines that don’t very revved and go on many short journeys.

Turbo engines require high-quality, clean oil to ensure an extended life. It is recommended to change the oil prior to the interval recommended by the manufacturer. Be aware of the level of oil and don’t let it fall below the its minimum.

A recall has been issued on an oil shortage on the vacuum pumps for brakes. in the absence of this, brake servo assistance can be decreased. Valvetronic engines require an air pump since they do not have a throttle plate, so they don’t generate the same amount of vacuum in the intake manifold.

Tuning these engines to boost power isn’t something to be avoided, so you do it professionally on a road that is paved. Avoid “wonder chips” and miracle power chips sold on ebay.

There are reports of heads breaking due to heat issues when after market tuners push the limits over the limit, and a limit of 330lb/ft is quoted by a variety of sources as a number that should not be over.

In January of 2015, BMW revamped the timing chain in order to fix an issue on some engines in which it stretched. It was also the TSB back in the year 2012, to repair the seal of oil for the tensioner of chain.

A recall occurred on 2014 . model year 2014 engines because of malfunctioning of the fuel pump with high pressure. The nickel plating in the pump wasn’t up to the standard that was required issue with the supplier, which has affected many car makers. Pumps in these engines are believed to be less prone to failure than the three-litre N54/N55 engines.



Please enter your comment!
Please enter your name here


Related Stories