M50 and M52 vs 1.5 K15B (Jimny): which engine is more reliable?

According to our risk index, the 1.5 K15B (Jimny) carries less risk than the M50 and M52: 14/100 (low 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 1.5 K15B (Jimny) has no documented serious faults.

Risk index

M50 and M52

High risk · 2 serious faults

Risk index

1.5 K15B (Jimny)

Low risk · 0 serious faults

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 202616 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 1.5 K15B (Jimny) reliable?

The 1.5 K15B in the Suzuki Jimny is a 102 hp naturally aspirated four-cylinder with a timing chain, simple and with no documented faults of its own. The only thing recorded in Europe is a 2018-2020 recall for the fuel pump, precautionary and with a definitive remedy.^[4][5][6]

See the of the 1.5 K15B (Jimny) fault

Side-by-side comparison

Comparison of M50 and M52 and 1.5 K15B (Jimny)
Item	M50 and M52	1.5 K15B (Jimny)
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	—	1,462 cm³
Timing	Chain	Chain
Power	150–193 hp	102 hp
Production	1990–2001^{[7][8][9][10]}	since 2018^[11][12][13]
Reliability
Risk index (what is it?)	52High risk	14Low risk
Documented faults	5	1
Of high or critical severity	2	0
Worst severity	Critical severity	Medium 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	Medium severity: Fuel pump with resin impeller that swells (recall)
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	None	1.5 K15B 102 hp (Jimny IV, 2018-present)^[4][5][6]
With cautionVersions to be cautious about	M50B20, 2.0 litre (150 hp; 1990-1995)^[14][15] M50B25, 2.5 litre (192 hp; 1990-1995)^[14][15] M52B20, 2.0 litre (150 hp; 1994-1999)^[8][14] M52B25, 2.5 litre (170 hp; 1995-1999)^[8][14] M52B28, 2.8 litre (193 hp; 1995-1999)^[8][14][16] M52TUB20, 2.0 litre (150 hp; 1998-2001)^[7][14] M52TUB25, 2.5 litre (170 hp; 1998-2000)^[7][14] M52TUB28, 2.8 litre (193 hp; 1998-2001)^[3][7][14]	None
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

1.5 K15B (Jimny)

Suzuki Jimny IV

Other comparisons

With the M50 and M52

With the 1.5 K15B (Jimny)

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
Problemas Suzuki JimnyTotalrenting · General press · consulted 30 October 2026 · in Spanish
Suzuki Jimny: problemas comunes y llamadas a revisióncar-recalls.eu · Other source · consulted 30 October 2026 · in Spanish
Suzuki Jimny Problemecarwiki.de · General press · consulted 30 October 2026 · in German
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
Suzuki K engineWikipedia · Other source · consulted 30 October 2026
Suzuki motor KWikipedia · Other source · consulted 30 October 2026 · in Spanish
Suzuki JimnyWikipedia · Other source · consulted 30 October 2026 · in Spanish
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