M50 and M52 vs 1.8 and 2.0 XU: which engine is more reliable?

According to our risk index, the 1.8 and 2.0 XU carries less risk than the M50 and M52: 39/100 (moderate risk) versus 52/100 (high risk). The M50 and M52 has 2 documented serious faults, the main one being «Cooling system failure (expansion tank, thermostat, pump and radiator)»; the 1.8 and 2.0 XU has 1 documented serious fault, the main one being «Premature timing belt breakage in the 16-valve engines».

Risk index

M50 and M52

High risk · 2 serious faults

Risk index

1.8 and 2.0 XU

Moderate risk · 1 serious fault

Lower risk

The index (0–100) weights the severity and frequency of the three most serious documented faults. How it is calculated

Reviewed on 2 November 202622 sources How we work

Is the M50 and M52 reliable?

The M52 and its predecessor the M50 are six-cylinder petrol engines that the sources describe as durable: Enginescope considers 300,000 km routine with the cooling circuit looked after. Watch the plastic cooling parts, VANOS, crankcase ventilation and oil leaks and, in the aluminium-block M52s built from 1995 to March 1998, cylinder wear caused by sulphur (Nikasil).^[1][2][3]

See the 5 of the M50 and M52 faults

Is the 1.8 and 2.0 XU reliable?

These are naturally aspirated 1.8 and 2.0-litre petrol engines with no serious documented design faults outside the 16-valve timing belt: the 1.8 16v built until late 1997 had a recall for premature breakages, and the 2.0 16v in the GTi-6 calls for shorter belt change intervals. The rest are minor faults: coolant and oil leaks, sensors and idle.^[4][5][6][7]

See the 5 of the 1.8 and 2.0 XU faults

Side-by-side comparison

Comparison of M50 and M52 and 1.8 and 2.0 XU
Item	M50 and M52	1.8 and 2.0 XU
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	—	—
Timing	Chain	Timing belt (dry)
Power	150–193 hp	90–167 hp
Production	1990–2001^{[8][9][10][11]}	1993–2002^{[12][13][14][15]}
Reliability
Risk index (what is it?)	52High risk	39Moderate risk
Documented faults	5	5
Of high or critical severity	2	1
Worst severity	Critical severity	Critical severity
Main faults	High severity: Cooling system failure (expansion tank, thermostat, pump and radiator) Critical severity: Premature cylinder wear (Nikasil coating) Medium severity: Worn VANOS seals	Critical severity: Premature timing belt breakage in the 16-valve engines Medium severity: Coolant leaks from the thermostat housing and radiator Medium severity: Oil consumption and oil leaks
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	None	1.8 8v 90-103 hp (XU7JB/LFX and XU7JP/LFZ, 1993-2001)^[4][5][16] 2.0 8v 121-123 hp (XU10J2C/RFX, until 1997)^[4][17]
With cautionVersions to be cautious about	M50B20, 2.0 litre (150 hp; 1990-1995)^[18][19] M50B25, 2.5 litre (192 hp; 1990-1995)^[18][19] M52B20, 2.0 litre (150 hp; 1994-1999)^[9][18] M52B25, 2.5 litre (170 hp; 1995-1999)^[9][18] M52B28, 2.8 litre (193 hp; 1995-1999)^[9][18][20] M52TUB20, 2.0 litre (150 hp; 1998-2001)^[8][18] M52TUB25, 2.5 litre (170 hp; 1998-2000)^[8][18] M52TUB28, 2.8 litre (193 hp; 1998-2001)^[3][8][18]	1.8 16v 110-112 hp (XU7JP4/LFY, 1995-2002)^[4][5][6] 2.0 16v 132-135 hp (XU10J4R/RFV, 1995-2002)^[6][7][21] 2.0 16v 150-167 hp (XU10J4/RFT/RFY S16 and XU10J4RS/RFS GTi-6 and VTS, 1993-2002)^[7][17][22]
AvoidVersions to avoid	None	None

Severity of each fault: green, low; amber, medium; red, high; dark red, critical. How we rate them

Cars that each one is fitted to

M50 and M52

1.8 and 2.0 XU

See the 9 models with the 1.8 and 2.0 XU

Other comparisons

With the M50 and M52

With the 1.8 and 2.0 XU

Compare other engines

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Sources

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

BMW 3 Series E36 320i (M52B20): reliabilityEnginescope · Other source · consulted 2 November 2026
BMW M52 reliabilityAutoscore · Other source · consulted 2 November 2026
BMW M52 Engine: Performance, Reliability, and TuningBMWBlog · Motoring press · consulted 2 November 2026
Peugeot 306: fiche fiabilitéCaradisiac · Motoring press · consulted 2 November 2026 · in French
Citroën Xsara: fiche fiabilitéCaradisiac · Motoring press · consulted 2 November 2026 · in French
Peugeot 406: fiche fiabilitéCaradisiac · Motoring press · consulted 2 November 2026 · in French
Peugeot 306 GTI-6 buying guide: powertrainPistonHeads · Motoring press · published 4 September 2016 · consulted 2 November 2026
BMW M52Wikipedia (inglés) · Other source · consulted 2 November 2026
BMW M52Wikipedia (alemán) · Other source · consulted 2 November 2026 · in German
BMW M50Wikipedia (inglés) · Other source · consulted 2 November 2026
BMW M50Wikipedia (alemán) · Other source · consulted 2 November 2026 · in German
PSA XU engineWikipedia (en) · Other source · consulted 2 November 2026
Peugeot 306Wikipedia (en) · Other source · consulted 2 November 2026
Citroën XsaraWikipedia (de) · Other source · consulted 2 November 2026 · in German
Citroën XsaraWikipedia (es) · Other source · consulted 2 November 2026 · in Spanish
Fiabilité Citroën Berlingo: pannes et avis des propriétairesFiches-auto.fr · Owners' forum · consulted 2 November 2026 · in French
Fiabilité Peugeot 306: pannes et avis des propriétairesFiches-auto.fr · Owners' forum · consulted 2 November 2026 · in French
BMW M50 / M52: problemas conocidosEnginescope · Other source · consulted 2 November 2026
Der BMW M50 Motor: Technische Daten, Probleme, Haltbarkeit & FahrzeuglisteCarWiki.de · Other source · consulted 2 November 2026 · in German
BMW Z3 Reliability Guide: Everything You Need to Know Before BuyingEuro Premium Parts · Technical documentation · consulted 2 November 2026
Fiabilité Peugeot 406: pannes et avis des propriétairesFiches-auto.fr · Owners' forum · consulted 2 November 2026 · in French
Fiabilité Citroën Xsara: pannes et avis des propriétairesFiches-auto.fr · Owners' forum · consulted 2 November 2026 · in French