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M50B25M50B25TU

M50B25, 2.5 litre (192 hp; 1990-1995) engine: faults and reliability

BMW M50 and M52 (seis cilindros en línea de gasolina, 2.0 / 2.5 / 2.8) version

With caution

The same reservations as the M50B20 apply: at this age, insist on a renewed cooling circuit and check for oil leaks and chain noise.[1][2]

Years
1990–1995
Power
192 hp
Faults that affect it
3
1 of high or critical severity
Cars that use it
2
in our database

9 sourcesHow we work

What changes in this version

2.5-litre version with 141 kW (192 hp) and 245 N·m (250 N·m in the 1992 TU). It powered the E36 325i from 1990 to 1995, with inlet VANOS from September 1992.[2][3][4][5]

Engine codes of this version: M50B25, M50B25TU.

Faults of the M50B25 engine

The documented engine faults that affect this version and its years, from most to least important.

  1. 1High severityFrequency: CommonCoolingCooling system failure (expansion tank, thermostat, pump and radiator)The most cited weak point of the M52: the expansion tank, the thermostat housing, the pump impeller and the radiator tanks are plastic and crack with age. If coolant is lost and the engine overheats, the cylinder head can be damaged.Appears at around 97,000 km
  2. 2Medium severityFrequency: CommonTimingWorn VANOS sealsVANOS, the M52’s variable valve timing, loses sealing when its internal seals harden: rough idle, lack of low-rev pull and higher consumption appear. It is repaired with a seal kit, but special tools are needed.Appears at around 97,000 km
  3. 3Medium severityFrequency: CommonLubricationOil leaks from the rocker cover, oil filter housing and other gasketsWith age the M52’s rubber gaskets harden: the most cited are the rocker cover gasket and the oil filter housing gasket, and on some M52TUs the plastic cover itself cracks. They should be watched so the oil level does not drop.

Cars fitted with the M50B25 engine

Open each car to see all its faults with this engine and what to check before buying it.

BMW

Frequently asked questions

Is the M50B25 engine reliable?

Our verdict is “With caution”. The same reservations as the M50B20 apply: at this age, insist on a renewed cooling circuit and check for oil leaks and chain noise.[1][2]

What faults does the M50B25 engine have?

The documented ones that affect this version, by importance: cooling system failure (expansion tank, thermostat, pump and radiator) (high severity), worn VANOS seals (medium severity) and oil leaks from the rocker cover, oil filter housing and other gaskets (medium severity).

Which cars use the M50B25 engine?

BMW Serie 3 E36 (1990–2000) and BMW Serie 5 E34 (1990–1996).[2][5][6][7][8][9]

Are you buying a car with the M50B25 engine?

We will put you in touch with a partner only if you authorise it in the form.

Do you have a car with this engine? Tell us which faults you have had and at how many kilometres. Report your fault.

Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. BMW M50 / M52: problemas conocidosEnginescope · Other source · consulted 2 November 2026
  2. Der BMW M50 Motor: Technische Daten, Probleme, Haltbarkeit & FahrzeuglisteCarWiki.de · Other source · consulted 2 November 2026 · in German
  3. BMW M50Wikipedia (inglés) · Other source · consulted 2 November 2026
  4. BMW M50Wikipedia (alemán) · Other source · consulted 2 November 2026 · in German
  5. BMW E36: motores y periodos de fabricaciónWikipedia (alemán) · Other source · consulted 2 November 2026 · in German
  6. BMW M52Wikipedia (alemán) · Other source · consulted 2 November 2026 · in German
  7. Der BMW M52 Motor: Technische Daten, Probleme, Haltbarkeit & FahrzeuglisteCarWiki.de · Other source · consulted 2 November 2026 · in German
  8. BMW E34 (1988-1996): motorizaciones, años de producción y puntos débilesWikipedia (de) · Other source · consulted 2 November 2026 · in German
  9. BMW 5 Series (E34): tabla de motoresWikipedia · Other source · consulted 2 November 2026