M43 1.6, 1.8 and 1.9 vs M50 and M52: which engine is more reliable?

According to our risk index, the M43 1.6, 1.8 and 1.9 carries less risk than the M50 and M52: 42/100 (moderate risk) versus 52/100 (high risk). The M43 1.6, 1.8 and 1.9 has 1 documented serious fault, the main one being «Failure of the plastic parts in the cooling system»; the M50 and M52 has 2 documented serious faults, the main one being «Cooling system failure (expansion tank, thermostat, pump and radiator)».

Risk index

M43 1.6, 1.8 and 1.9

Moderate risk · 1 serious fault

Lower risk

Risk index

M50 and M52

High risk · 2 serious faults

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

Reviewed on 2 November 202617 sources How we work

Is the M43 1.6, 1.8 and 1.9 reliable?

The M43 (1993-2002) is an 8-valve petrol four-cylinder with a timing chain that Autohints describes as one of BMW’s most durable engines of the nineties. The faults the sources cite are with ancillaries: plastic cooling parts, oil leaks from the gaskets, rough idle, ignition and, in some versions, the DISA valve.^[1][2][3]

See the 5 of the M43 1.6, 1.8 and 1.9 faults

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).^[4][5][6]

See the 5 of the M50 and M52 faults

Side-by-side comparison

Comparison of M43 1.6, 1.8 and 1.9 and M50 and M52
Item	M43 1.6, 1.8 and 1.9	M50 and M52
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	—	—
Timing	Chain	Chain
Power	102–118 hp	150–193 hp
Production	1993–2002^[2][7][8]	1990–2001^{[9][10][11][12]}
Reliability
Risk index (what is it?)	42Moderate risk	52High risk
Documented faults	5	5
Of high or critical severity	1	2
Worst severity	High severity	Critical severity
Main faults	High severity: Failure of the plastic parts in the cooling system Medium severity: DISA intake manifold valve with play and noise Low severity: Oil leaks from gaskets (rocker cover, front cover and crankcase breather)	High severity: Cooling system failure (expansion tank, thermostat, pump and radiator) Critical severity: Premature cylinder wear (Nikasil coating) Medium severity: Worn VANOS seals
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	None	None
With cautionVersions to be cautious about	M43B16, 1.6 litre (102 hp; 1993-1999)^[1][2][3] M43B18, 1.8 litre (115 hp; 1993-1999)^[1][13] M43TUB19, 1.9 litre (105 hp; 1998-2002)^[1][3][14] M43TUB19, 1.9 litre (118 hp; 1998-2002)^[1][3][14]	M50B20, 2.0 litre (150 hp; 1990-1995)^[15][16] M50B25, 2.5 litre (192 hp; 1990-1995)^[15][16] M52B20, 2.0 litre (150 hp; 1994-1999)^[10][15] M52B25, 2.5 litre (170 hp; 1995-1999)^[10][15] M52B28, 2.8 litre (193 hp; 1995-1999)^[10][15][17] M52TUB20, 2.0 litre (150 hp; 1998-2001)^[9][15] M52TUB25, 2.5 litre (170 hp; 1998-2000)^[9][15] M52TUB28, 2.8 litre (193 hp; 1998-2001)^[6][9][15]
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

M43 1.6, 1.8 and 1.9

M50 and M52

Other comparisons

With the M43 1.6, 1.8 and 1.9

With the M50 and M52

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Sources

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

BMW M43B18 1.8L 115hp inline-4 cylinder engineAutoHints · Technical documentation · consulted 2 November 2026
Der BMW M43 Motor: Technische Daten, Probleme, Haltbarkeit & FahrzeuglisteCarWiki.de · Other source · consulted 2 November 2026 · in German
BMW M43: problemas conocidosEnginescope · Other source · consulted 2 November 2026
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
BMW M43Wikipedia (inglés) · Other source · consulted 2 November 2026
BMW M43Wikipedia (alemán) · Other source · consulted 2 November 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
BMW 3 Series E36 Reliability Guide: Everything You Need to Know Before BuyingEuro Premium Parts · Technical documentation · consulted 2 November 2026
316i M43: 17 Jahre, Standhaftigkeit erhöhen (E46)BMW-Syndikat (foro) · Owners' forum · consulted 2 November 2026 · in German
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