M104 vs OM656

Side-by-side reliability comparison

Higher reliability score
M104 BEST 85/100
+3 points over OM656
0 / 100
BEST M104 Mercedes-Benz
0 / 100
BUY OM656 Mercedes-Benz

Specifications

M104
OM656
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
BEST
BUY
Reliability
85
82
Years
1990--1997
2017--present
Displacement
3199 cc
2999 cc
Layout
I6
I6
Type
Petrol Na
Diesel
Power
193--231 hp
243--330 hp
Known Issues
1
2
Total Risk Cost
€500--€2,000
€500--€2,000

Character

M104

"W124/R129/W140 inline-6. One of Mercedes' most reliable engines. Bulletproof bottom end. Wiring harness biodegrades (uses soy-based insulation). Head gasket solid. 400k+ km possible."

OM656

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

Issues Comparison

M104 1

▲ HIGH
Wiring harness biodegradation €500--€2,000 100,000 km--200,000 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

M104 0

No models listed.

OM656 3

E 400d W213 2016--2024 Sedan GLE 350d W166 2015--2019 SUV S 350d W222 2013--2020 Sedan
Full M104 Report Full OM656 Report