The BMW M51 is an inline-6 cylinder

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 ...

produced by the Upper Austrian BMW plant in

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 ...

from July 1991 through February 2000. Its predecessor is the

BMW M21 The BMW M21 is a straight-six diesel engine developed by the Bavarian engine manufacturer BMW. It has swirl chamber injection and is based on the M20 petrol engine and was produced for BMW by the Upper Austrian Steyr engine plant from 1983 to ...

, the successor is the

BMW M57 The BMW M57 is a straight-6 diesel engine produced from 1998 up to 2013 in BMW's upper Austrian engine plant in Steyr. Description The M57 is a water-cooled and turbocharged inline six cylinder diesel engine with common-rail-injection. It w ...

Description

The M51 is a water-cooled and turbocharged inline six-cylinder diesel engine with a Bosch VP20- swirl-chamber-injection. The displacement is and the

compression ratio The compression ratio is the ratio between the volume of the cylinder and combustion chamber in an internal combustion engine at their maximum and minimum values. A fundamental specification for such engines, it is measured two ways: the stati ...

is 22.0:1. Some engine variants have an intercooler in addition to the turbocharger, they can be identified by the ''tds''. The M51 is an engine made of cast iron, it has one chain driven overhead camshaft and two valves per cylinder. Compared to the M21 the M51 now has tappets and a hydraulic valve lash adjustment. The fuel injection in the first engines is controlled by the ECU Bosch DDE 2.1, which was replaced after the first technical revision by the DDE 2.2. This results in greater torque at lower revs. For lubrication SAE 5W-40 oil is used. Applications: * 1991 - 1996 E36 325td (M51D25 UL) * 1996 - 1998 E36 325td (M51D25TÜ UL) * 1993 - 1996 E36 325tds (M51D25 OL) * 1996 - 1998 E36 325tds (M51D25TÜ OL) * 1992 - 1996 E34 525td (M51D25 UL) * 1991 - 1996 E34 525tds (M51D25 OL) * 1996 - 2000 E39 525tds (M51D25TÜ OL) * 1996 - 2000 E39 525td (M51D25TÜ UL) * 1996 - 2000 E38 725tds (M51D25TÜ OL) * 1995 - 2001

Land Rover Land Rover is a British brand of predominantly four-wheel drive, off-road capable vehicles, owned by multinational car manufacturer Jaguar Land Rover (JLR), since 2008 a subsidiary of India's Tata Motors. JLR currently builds Land Rovers ...

Range Rover 2.5 D/DSE * 1995 - 2001

Opel Omega The Opel Omega is an executive car engineered and manufactured by German automaker Opel between 1986 and 2004. The first generation, the Omega A (1986–1993), superseded the Opel Rekord. It was voted European Car of the Year for 1987, and wa ...

* 1992

UMM Alter II The UMM Alter II is a Portuguese automobile produced by UMM from 1986–1994. UMM Alter II Phase I In 1986 the Alter II was released by the Portuguese automobile manufacturer União Metalo-Mecânica (UMM). It featured a new 4-speed manual ge ...

(single example; engine, gearbox, and electronics were fitted by BMW in Munich)

References

Die BMW-Sportdiesel: Von 524td E28 über 530d E39 bis BMW M550d F10
(german) Opel Omega B 2.5 TD 96 kW 130 PS - Motor: 25DT, X25DT, X25TD - Eco Optimierung / Leistungssteigerung
(german) Etzold
So wird's gemacht: pflegen – warten – reparieren. Band 102, BMW 5er E39
Delius Klasing Verlag. Pages 12 and 13 (german)
/ref> Übersicht der Motorölqualitäten
Page 7 (german)

M51 M51 or M-51 may refer to: * M-51 (Michigan highway), a state highway in Michigan * M51 highway (Russia) * M51 (Cape Town), a Metropolitan Route in Cape Town, South Africa * M51 Skysweeper, an anti-aircraft gun * M51 MACI mine * M51 SLBM, a Fre ...

1991 introductions Diesel engines by model Straight-six engines {{BMW automotive diesel engines: 1980s to 2000s

Description

See also

References