The BMW M47 and

Rover Group The Rover Group plc was the British vehicle manufacturing conglomerate known as "BL plc" until 1986 (formerly British Leyland), which had been a state-owned company since 1975. It initially included the Austin Rover Group car business (comprisi ...

M47R are

straight-4 A straight-four engine (also called an inline-four) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. The vast majority of automotive four-cylinder engines use a straight-four layout (with the ...

Diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

s. Variants were manufactured by BMW from 1998 to 2007. BMW gradually adopted high-pressure

common rail Common rail direct fuel injection is a direct fuel injection system built around a high-pressure (over ) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors (or pump nozzles). High-pressure injection ...

fuel injection Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All comp ...

systems over the lifetime of the M47.

M47D20

The original M47 diesel engine featured non-common-rail direct fuel injection and a block. First seen in 1998, the M47D20 produced and in its original 320d/520d guise, and with in the 318d variant. All M47 engines have one Swirl and one Tangential intake port per cylinder, which can each improve performance under different conditions. These features are not to be confused with swirl flaps, which were introduced in the M47TUD20. Applications: * and ** 2001–2003 E46 318d * and ** 1999–2001 E46 320d ** 2000–2003 E39 520d

M47R

(UK) and

Steyr Steyr (; Central Bavarian: ''Steia'') is a statutory city, located in the Austrian federal state of Upper Austria. It is the administrative capital, though not part of Steyr-Land District. Steyr is Austria's 12th most populated town and the 3rd l ...

(Austria), worked together to modify the M47D20 to create a transverse configuration for use in the

Rover 75 The Rover 75 is an executive car manufactured initially by the Rover Group and later by MG Rover, under the Rover marque and available over a single generation with front-wheel drive in either saloon/sedan or station wagon/estate configuratio ...

front wheel drive saloon, as well as their all-wheel-drive

Land Rover Freelander The Land Rover Freelander is a compact luxury crossover SUV that was manufactured and marketed by Land Rover from 1997 to 2015. The second generation was sold from 2007 to 2015 in North America and the Middle East as the LR2 and in Europe as the ...

. The same engine was later deployed by

MG Rover MG Rover Group was the last domestically owned mass-production car manufacturer in the British motor industry. The company was formed when BMW sold the car-making and engine manufacturing assets of the original Rover Group to the Phoenix Consor ...

in the Rover 75 Tourer and

MG ZT The MG ZT is a car which was produced by MG Rover from 2001 to 2005. It was offered in saloon and estate versions, the latter designated as the MG ZT-T. Styling is similar to the Rover 75, upon which it was based, although various modifications, ...

. The M47R ("M47 Rail") differs from the original design by the introduction of common-rail technology, a transverse orientation, different

turbocharger In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

s and more sophisticated systems for temperature management. However, the core heads of the M47R and M47D20 are the same. Combining a common-rail system with a relatively small engine capacity created engine temperature problems. More hardware was added to help control temperatures which also helped to escalate weight, fuel consumption, and manufacturing costs. Th
BMW Steyr plant
manufactured and supplied M47R engines with the same power output as the M47D20 from 1999 to 2006. Applications: * 1999–2004 Rover 75 CDT * 1999–2005 Rover 75 CDTi * 2001–2006

* 2001–2004 MG ZT CDT * 2001–2005 MG ZT CDTi

M47TUD20

The all wheel drive BMW X3 and rear-wheel drive BMW 320d models, built approximately between September 2001 and December 2004, were fitted with the M47TU ("M47 Technical Update"). The exact production week is not known and was probably later than Production Week 33 in 2001 (e.g. one cannot rely on a UK 51 plate registered BMW 320d to have the M47TU). The engine capacity was expanded to , and it retained the common-rail injector system that had proven popular in the smaller M47R and larger M57 engines. These changes empowered BMW to increase torque and improve fuel consumption, especially at lower revs. However, these modifications added to overall weight and emissions raised accordingly. In the UK, the new characteristics of the M47TU were sufficient to lift the BMW 320d into the next highest insurance bracket, and the next highest band for

Vehicle Excise Duty Vehicle Excise Duty (VED; also known as "vehicle tax", "car tax", and more controversially as "road tax", and formerly as a "tax disc") is an annual tax that is levied as an excise duty and which must be paid for most types of powered vehicles which ...

(Road Ta

The M47TU was regarded as so good that BMW made it available in the 320Cd Coupé. The M47TUD20 introduced new common failure points. Chief among these was a new ' swirl flap' mechanism embedded in the

inlet manifold In automotive engineering, an inlet manifold or intake manifold (in American English) is the part of an engine that supplies the fuel/air mixture to the cylinders. The word '' manifold'' comes from the Old English word ''manigfeald'' (from th ...

. This consisted of a number of butterfly valves within each individual inlet tract, which are secured to an actuating rod via two small screws. It has become clear that over time these screws can come loose via vibration etc. When this happens they can end up being drawn into the respective cylinder, causing significant damage to the piston, cylinder head, and valves. If unlucky further damage can be caused to the turbo if the screw then makes its way through the exhaust valve into the manifold and subsequently into the turbo. These failures have occurred in such quantity that a number of specialist BMW magazines have featured articles on the problem including information on how to remove the swirl flaps. For those who wish to perform some preventive maintenance on the M47TUD20 engine, there are companies who supply and/or fit blanking plugs to allow the removal of these swirl flaps altogether. BMW addressed the problem by introducing stronger swirl flaps and larger diameter spindles – made from plastic – in 2006. Applications: * and ** 2003–2005 E46 318d * and ** 2001–2005 E46 320d ** E83 X3 2.0d (up to end of 2006)

M47TU2D20

The engine was updated again in 2004 as the M47TU2D20. Still at , it produced more power across the range. Applications: * and ** E87 118d ** E90/E91 318d * and ** E60/E61 520d ** E87 120d ** E90/E91 320d ** E83 X3 2.0d (end of 2006 onwards)

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