The Most Worst And Reliable BMW Engine Reviews

When buying a used BMW engine, the issue of the engine is even more important than with other, cheaper cars. Here, the emotions of the rear-wheel drive and power are the most important. BMW offers a lot of units that meet these requirements, so much so that it is not always known what is exactly under the hood.

Most Worst Reliable BMW Engines

Sometimes even one designation (e.g. 320i) may denote several types of the engine that differ in power or design. Knowledge about your engine version is crucial, because not all of them use the same parts.

As a rule, only the 10-cylinder unit S85 and the 4-cylinder N13, N20 and N26 break out. After determining the number of cylinders, we find the type of fuel (B – gasoline; D – diesel), cylinder capacity (20 – 2 liters, 30 – 3 liters etc.) and a code related to the design, informing, among other things, about factory changes made (eg TU – Technische Uberarbeitung, i.e. technical modification / corrected version). Exemplary designation: M57D30TU – diesel 3.0, type M57, after facelift.

Nobody should complain about the lack of choice in BMW gasoline engines. In our list, we present the 15 most popular, which can be found in virtually every model of the Bavarian manufacturer. Due to the design, the older units have multi-point, newer direct fuel injection.

As a result, they need less fuel, but the carbon deposits on the head settle faster. This is because air is not flowing through the valves. The vast majority of engines also have variable valve phases and a Valvetronic variable lift system, although it was introduced somewhat later.

Below we present an overview of selected engines, their use in models and typical faults that plague them.

Most Worst & Reliable BMW Engines

BMW is a brand with so many units that you can get lost in them. Introducing the 15 most popular petrol engines from BMW- both new and used.

4-Cylinder BMW Engines

  • N42 Engine
  • N46 Engine
  • N45 Engine
  • N43 Engine
  • N20 / N13 Engine

6-Cylinder BMW Engines

  • M52 Engine
  • M54 Engine
  • M56 Engine
  • N52 Engine
  • N53 Engine
  • N54 Engine
  • N55 Engine

8-Cylinder BMW Engines

  • N62 Engine
  • N63 Engine

12-Cylinder BMW Engines

  • N73 Engine
  • N74 Engine

4-Cylinder BMW Engines

N42 Engine

  • Naturally aspirated, capacity 1.8-2.0
  • Multi-point fuel injection
  • VANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Series 3 ( E46 2001-2004)

The engine debuted in 2001 and was only fitted to the 3 Series E46 in two versions, 116 and 143 hp. This is the first BMW engine in which the company used the Valvetronic system that controls valve lift.

It makes LPG assembly difficult, but it should not be a barrier for a qualified specialist. The engine is not very malfunctioning – in the early models only the timing chain is pulled out.

N46 Engine

  • Naturally aspirated, capacity 1.8-2.0
  • Multi-point fuel injection
  • VANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Series 1 (E81-E87)
  • Series 3 (E46 – Up to 2005 / E90 – 2005-2007)
  • X3 (E83)
  • Z4 (E85)
  • X1 (E84)
  • Series 5 (E60 2003-2007 )

The N46 BMW engine has a similar structure to the N42 – it also features the Valvetronic system and VANOS variable valve timing. This engine additionally uses two balancer shafts and a DISA flap in the inlet to change the inlet length.

It can loosen on the axle and rattle, fortunately there are replacements available. In N46, problems are no longer caused by a stretching timing chain, but oil leaks from under the valve cover gasket and from the vacuum pump. At high mileage, the impeller of the fuel pump also breaks.

N45 Engine

  • Naturally aspirated, capacity 1.6-2.0
  • Multi-point fuel injection
  • VANOS valve phases variable
  • No Valvetronic system

Application:

  • Series 1 (E81-E87)
  • Series 3 (E90, 316i only)

The N45 BMW engine replaced the 1.6 liter N40 in 2004. The Valvetronic system was not installed in it, thanks to which the engine is lighter and simpler in design. However, this does not mean that it is not bothered by failures.

The most famous are the faults of the timing chain tensioner, which the manufacturer used to replace under warranty. If he did not install the modernized type, the problem returned after 20-30 thousand. Fortunately, the exchange is not an expensive operation.

N43 Engine

  • Naturally aspirated, capacity 1.6-2.0
  • Direct fuel injection V
  • ANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Series 1 (E81-E87)
  • Series 3 (E90, E91, E92)
  • Series 5 (E60) – all after 2007

The introduction of direct injection reduced fuel consumption, but also brought new problems for users. The first is the fact that this BMW engine cannot be fitted with a gas installation and must only run on the cleanest fuel. If the gasoline is even slightly sulphated, it can have serious consequences.

In addition, the unit is not free from faults – ignition coils break (symptom – weaker power and shudder at low revs) and injectors, as well as carbon deposits in the head. It is also better to change the oil not every 30,000 kilometers, as recommended by the manufacturer, but even twice as often.

N20 / N13 Engine

  • Turbocharged, capacity 1.6-2.0
  • Direct fuel injection
  • VANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Mini Cooper S
  • Series 1 (F20)
  • Series 2 (F22)
  • Series 3 (F30)
  • Series 5 (F10)
  • X1 (E84)
  • X3 (F25)
  • X4 (F26)
  • Z4 (E89)

The turbocharged unit was available in two capacity variants – 2.0 N20 (found in BMW cars) and 1.6 N13, constructed together with Peugeot-Citroen and assembled, in addition to some cars of these two manufacturers, also in Mini Cooper S.

French cars often had breakdowns of the timing chain tensioner, and in addition to collecting carbon deposits in the head. If we change the oil more often (every 15,000 kilometers) and from time to time “chase” the engine at high speed, the problem should appear later.

If we want to buy the 245 HP variant of the N20 BMW engine, we should check if it was not covered by the BMW Repair Inclusive repair package. The manufacturer carried it out due to oil pump faults, so the engine did not have proper lubrication. If the engine as part of the package has the pump module and timing chain replaced, we will avoid spending several thousand dollars at the beginning.

6-Cylinder BMW Engines

M52 Engine

  • Naturally aspirated, capacity 2.0, 2.5, 2.8
  • Multi-point fuel injection
  • Variable valve phases VANOS (from 1998 on both camshafts)
  • No Valvetronic system

Application:

  • Series 3 (E36 and E46 – Retired in 2000)
  • Series 5 (E39)

An old engine, used in models from the 90s. In Europe it was used with an aluminum block, in the USA – with a cast iron one. In 1998, it underwent a modernization, which added a camshaft variator on the shaft controlling the exhaust valves and the DISA variable length manifold valve.

The unit is known for its longevity, but in order to cover hundreds of thousands of kilometers without failure, the oil separator, i.e. the odor filter, must be replaced regularly (preferably every third oil change). Otherwise, oil deposits will cover the pneumothorax.

M54 Engine

  • Naturally aspirated, capacity 2.0, 2.5, 2.8
  • Multi-point fuel injection
  • VANOS valve phases variable
  • No Valvetronic, electronically controlled throttle

Application:

  • Series 3 (E46)
  • Series 5 (E39 / E60)
  • Series 7 (E65 / 66)
  • X3 (E83)
  • X5 (E53)
  • Z3 (E36 / E85)

BMW engines most often “come” to us from Great Britain. The unit used in many models is considered the best 6-cylinder engine of the Bavarian brand and achieves high prices. In fact, the only failure that occurred was the defective electronic thermostats.

It is also better, as with the M52, to change the oil separator regularly. The engine has a hydraulic valve clearance compensation, therefore it works with LPG without any problems.

M56 Engine

  • Naturally aspirated, capacity 2.0, 2.5, 2.8
  • Multi-point fuel injection
  • VANOS valve phases variable
  • No Valvetronic, electronically controlled throttle

Application:

  • Series 3 (E46) with the designation 325iA – US market

It’s exotic with us. The M56 BMW engine is nothing but the M54 engine, rebuilt to meet US emissions standards. How to distinguish it? After the oil filler neck – it is on the right side of the engine, not in the center of the valve cover. Better not to risk buying it, because it is difficult to choose the right parts for it.

N52 Engine

  • Naturally aspirated, capacity 2.5-3.0
  • Multi-point fuel injection
  • VANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Series 1 (E87)
  • Series 3 (E90)
  • Series 5 (E60 / F10)
  • Series 6 (E63 / 64)
  • X1 (E84)
  • X3 (E83)
  • X5 (E70)
  • Z4 (E85 / E86 / E89)

Although this BMW engine made its debut in 2004, its career in Europe ended in 2007, while in the States it lasted until 2015. It is also the last BMW 6-cylinder with multi-point injection. The most common defect is rattling of the hydraulic valve lash adjusters. This is a “ride-on” fault. The only way out is a costly head replacement.

N53 Engine

  • Naturally aspirated, capacity 2.5-3.0
  • Direct fuel injection
  • VANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Series 3 (E90-E93)
  • Series 5 (E60)
  • Series 5 (F10)

The N53 BMW engine differs from the twin N52 by replacing traditional multi-point injection with direct fuel injection. The engine was only offered in Europe for just five years, until 2011. As in the older version, valve lash adjusters clatter, and in addition, carbon build up in the head and spoil the fuel pumps.

N54 Engine

  • Biturbo engine, capacity 3.0
  • Direct fuel injection
  • VANOS valve phases variable
  • No Valvetronic system

Application:

  • Series 1 (E82-E88)
  • Series 3 (E90-E93)
  • Series 5 (E60)
  • Series 7 (F01)
  • X6 (E71)
  • Z4 (E89)

A replacement for the M54 engine, famous for its durability, produced in 2006-2015. It has dual boost and direct fuel injection, but without Valvetronic yet. Much more popular in the US than in Europe. Traditionally, for BMW engines, carbon deposits accumulate in it, and in addition, the fuel pump and the drain valve of the turbocharger system are defective.

N55 Engine

  • Biturbo engine, capacity 3.0
  • Direct fuel injection
  • VANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Series 1 (E82 / F20)
  • Series 2 (F22)
  • Series 3 (E90 / F30)
  • Series 5/5 GT (F07 / F10)
  • Series 7 (F01)
  • X3 (F25)
  • X4 (F26)
  • X5 (E70 / F15)
  • X6 (E71 / F16)

Compared to its predecessor (N54), it has only one turbocharger. This does not prevent the BMW brand from calling it the Twin Power Turbo. In production since 2009. Despite his young age, it can be said that he did not take over the problems of the N54 BMW engine. Sometimes there are only oil leaks from under the valve cover and leaks in the pipes at the turbocharger.

8-Cylinder BMW Engines

N62 Engine

  • Naturally aspirated, capacity 3.6-4.8
  • Multi-point fuel injection
  • VANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Series 5 (E60)
  • Series 7 (E65 / 66)
  • Series 6 (E63 / 64)
  • X5 (X53 / E70)

The successor of the M62 BME engine, produced between 2002 and 2010. Still on the old type of injection, but already with the modern Valvetronic system and variable valve phases. Separate timing chains are used for each head, which drive both shafts simultaneously.

The engine is plagued by two leakage failures. Valve seals do not show it (which is manifested by smoking), as well as the pipe under the suction manifold, thus refrigerant fluid escapes. Removing faults requires removing the engine, which translates into costs of several thousand dollars.

N63 Engine

  • Biturbo engine, capacity 4.4
  • Direct fuel injection
  • VANOS valve phases variable
  • Valvetronic introduced in 2012

Application:

  • Series 5/5 GT (F10 / F07 / F30)
  • Series 6 (F12 / F13)
  • Series 7 (F01 / G11)
  • X5 (F15)
  • X6 (E71)

The “Black Sheep” in the BMW engine range. Seizure caused by high oil consumption was noted fairly quickly (after 100,000 kilometers). There was no end to the service actions, and the producer mentioned in their pages, among others injectors and a vacuum pump. The problem, however, was in the piston rings with insufficient durability. After the modernization of the unit in 2012, the problem ceased.

12-Cylinder BMW Engines

N73 Engine

  • Naturally Aspirated, capacity 6.0-6.7
  • Direct fuel injection
  • VANOS valve phases variable
  • Variable valve lift Valvetronic

Application:

  • Series 7 (E65 / 66)
  • Rolls-Royce Phantom

The powerful BMW engine was used not only in the 7 series, but also in the Rolls-Roys Phantom (6.8 V12). Today it is difficult to find on the secondary market. Due to the presence of direct injection, it is also exposed to soot clogging of the inlet channels. It is difficult to find more common failures because little is written about them for such large engines.

N74 Engine

  • Biturbo engine, displacement 6.0-6.6
  • Direct fuel injection
  • VANOS valve phases variable
  • No Valvetronic system

Application:

  • Series 7 (F01)
  • Rolls-Royce Wraith
  • Rolls-Royce Dawn
  • Rolls-Royce Ghost

The flagship engine of the Bavarian manufacturer. To meet only the strongest version of the 7 series and Rolls-Roys Wraith (variant with 632 HP).

Technically, these are two N55 BMW engine combined into one block. It is difficult to find any information regarding the failure rate, while the astronomical repair costs should not come as a surprise with such a large and complicated engine.

Conclusion

A given BMW engine can only be verified after its designation has been checked. There is always a letter at the beginning – M and N refer to standard engines in passenger cars, S stands for a special variant engine, e.g. from M3, M5. Two digits are then used to indicate the number of cylinders. They are allocated as follows:

  • Numbers 40-47 = Four cylinder engines
  • Numbers from 50 = Six cylinder engines
  • Numbers from 60 = Eight cylinder engines
  • Numbers from 70 = Twelve cylinder engines
Hi, my name is Jasmine. My hobby is writing articles about automotives and autospruce.com is one of the blogs of many of our communities. Thank you for reading our article and hope you enjoy it.

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