M50/M52 vs B58

Side-by-side reliability comparison

Higher reliability score
B58 BEST 89/100
+3 points over M50/M52
0 / 100
BEST M50/M52 BMW
0 / 100
BEST B58 BMW

Specifications

M50/M52
B58
Brand
BMW
BMW
Verdict
BEST
BEST
Reliability
86
89
Years
1990--2001
2015--present
Displacement
2494 cc
2998 cc
Layout
I6
I6
Type
Petrol Na
Petrol Turbo
Power
150--193 hp
326--387 hp
Known Issues
5
7
Total Risk Cost
€430--€2,200
€2,100--€8,050

Character

M50/M52

"Smooth, linear inline-six with bulletproof internals — 300,000 km is routine. Budget a full cooling-system refresh (plastic tank, impeller, thermostat housing) and expect VANOS seals and the oil separator to need doing. Only trap: European M52 built 1995 to early 1998 had Nikasil bores that sulphur fuel destroyed; ask for a leak-down test or proof of a replacement block. M50 and M52TU are not affected."

B58

"Arguably BMW's best modern petrol: a smooth, strong 3.0 turbo six from the 340i to the Toyota Supra, with no engine-destroying pattern fault. What does go wrong is bolt-on: coolant loss (expansion tank, water pump), the PCV diaphragm in the valve cover (oil smoke) and, on 2018-2022 engines, a plastic part in the oil pump. Forged crankshaft, closed-deck block; strong tuning base."

Issues Comparison

M50/M52 5

◆ CRITICAL
Nikasil cylinder-bore wear (M52 built 1995 to March 1998, non-US) N/A--N/A 48,000 km--N/A
● MODERATE
Crankcase ventilation (CCV / oil separator) clogs — oil consumption, rough idle €100--N/A 130,000 km--195,000 km
● MODERATE
Cooling system plastics (tank, housing, impeller) €150--€1,700 97,000 km--240,000 km
○ MINOR
VANOS oil seal wear (M50TU from 1992, M52, M52TU) €80--€200 120,000 km--200,000 km
○ MINOR
Valve cover / oil pan gasket leaks €100--€300 150,000 km--∞

B58 7

▲ HIGH
Oil pump plastic ring cracks — oil pressure loss (2018-2022 engines) €1,100--€5,500 48,000 km--N/A
● MODERATE
Coolant loss — expansion tank or cap, electric water pump, low-temperature circuit N/A--N/A 97,000 km--161,000 km
● MODERATE
PCV diaphragm in the valve cover and valve cover gasket — oil smoke, oil leaks €920--€2,350 113,000 km--161,000 km
○ MINOR
VANOS solenoid wear N/A--N/A 100,000 km--161,000 km
○ MINOR
Crankshaft guide bearing wear — early manual F30 340i (service action) €0--N/A N/A--N/A
○ MINOR
Oil filter shears off in its housing N/A--N/A N/A--N/A
○ MINOR
Plastic charge pipe crack €80--€200 60,000 km--150,000 km

Models

M50/M52 12

3 Series E36 1990--1994 3 Series E36 1990--1995 5 Series E39 1996--2000 3 Series E36 1994--1999 3 Series E46 1998--2001 5 Series E39 1996--2000 3 Series E36 1995--1999 3 Series E46 1998--2000 5 Series E39 1996--2000 3 Series E36 1995--1999 Z3 E36/7 1997--2000 3 Series E46 1998--2000

B58 26

2 Series F22 2016--2021 5 Series F10 2016--2017 1 Series F20 2016--2019 7 Series G11 2016--2022 GR Supra A90 2019--present 6 Series F13 2015--2018 4 Series F32 2016--2020 6 Series G32 2017--2023 3 Series G20 2025--present 3 Series F30 2015--2019 X5 G05 2020--present GR Supra A90 2022--present X6 G06 2019--present X5 G05 2018--present X3 G01 2017--2024 5 Series G30 2017--2023 8 Series G15 2018--present X7 G07 2019--present 3 Series G20 2019--2025 Z4 G29 2019--present 4 Series G22 2020--present X4 G02 2018--present 2 Series G42 2022--present 7 Series G70 2023--present 5 Series G60 2024--present 340i F30 LCI 2015--2019 Sedan
Full M50/M52 Report Full B58 Report