M112 vs OM656

Side-by-side reliability comparison

Higher reliability score
M112 BUY 84/100
+2 points over OM656
0 / 100
BUY M112 Mercedes-Benz
0 / 100
BUY OM656 Mercedes-Benz

Specifications

M112
OM656
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
BUY
BUY
Reliability
84
82
Years
1997--2006
2017--present
Displacement
3199 cc
2999 cc
Layout
V6
I6
Type
Petrol Na
Diesel
Power
170--245 hp
243--330 hp
Known Issues
7
2
Total Risk Cost
€1,280--€3,625
€500--€2,000

Character

M112

"Three-valve V6 from the last simple Mercedes era. Nothing expensive inside; the harmonic balancer rubber and the crank sensor are the two things to check. Runs for ever on synthetic oil."

OM656

"Flagship modern MB diesel. Inline-6 smoothness returns. MHEV. GLE/GLS/S-Class. Excellent highway. Early data strong."

Issues Comparison

M112 7

▲ HIGH
Harmonic balancer (crank pulley) rubber delaminates €280--€650 N/A--N/A
● MODERATE
Oil leaks — valve-cover gaskets, front crank seal (V6), rear main seal (V8) N/A--N/A N/A--N/A
● MODERATE
Air suspension / Airmatic failure (S/ML models) €600--€2,000 100,000 km--180,000 km
○ MINOR
Oil sludge from conventional oil on long FSS intervals (MY1998-2001) N/A--N/A N/A--N/A
○ MINOR
Crankshaft position sensor fails when hot — stall or hot no-start €50--€125 N/A--N/A
○ MINOR
Spark plugs + ignition coils (V6/V8) €200--€500 80,000 km--150,000 km
○ MINOR
Coolant system: water pump, thermostat, expansion tank €150--€350 100,000 km--180,000 km

OM656 2

● MODERATE
DPF + EGR — diesel city driving concern €400--€1,200 60,000 km--120,000 km
○ MINOR
AdBlue / SCR system consumption and faults €100--€800 30,000 km--∞

Models

M112 12

E-Class W210 1997--2002 C-Class W203 2001--2005 E-Class W211 2002--2005 E-Class W210 1997--2002 C-Class W202 1997--2000 S-Class W220 1998--2005 E-Class W210 1997--2002 C-Class W203 2001--2005 CLK W209 2002--2005 S-Class W220 1998--2005 ML 320 W163 1997--2005 SUV ML 350 W163 2003--2005 SUV

OM656 3

E 400d W213 2017--2024 Sedan GLE 350d W166 2015--2019 SUV S 350d W222 2017--2020 Sedan
Full M112 Report Full OM656 Report