M104 vs OM654
Side-by-side reliability comparison
Reliability score
Tied
85/100
0
/ 100
BEST
M104
Mercedes-Benz
0
/ 100
BEST
OM654
Mercedes-Benz
Specifications
M104
OM654
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
BEST
BEST
Reliability
85
85
Years
1990--1997
2016--present
Displacement
3199 cc
1950 cc
Layout
I6
I4
Type
Petrol Na
Diesel
Power
193--231 hp
150--245 hp
Known Issues
1
2
Total Risk Cost
€500--€2,000
€500--€1,500
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."
OM654
"Best modern MB diesel. Aluminium block, low friction. Long-distance champion."
Issues Comparison
M104 1
▲ HIGH
Wiring harness biodegradation
OM654 2
○ MINOR
DPF — better than older MB diesels but still diesel
○ MINOR
Minor EGR fouling (best-in-class but not immune)
Models
M104 0
No models listed.
OM654 47
B-Class
A-Class
GLA
A-Class
C-Class
C-Class
GLC
E-Class
GLC
E-Class
GLE
E-Class
C-Class
C-Class
GLC
GLC
E-Class
C-Class
E-Class
GLC
C-Class
C-Class
GLC
E-Class
CLA
A-Class
CLA
B-Class
GLA
GLA
A-Class
E-Class
S-Class
GLE
E-Class
G-Class
E-Class
G-Class
G-Class
S-Class
S-Class
S-Class
GLE
S-Class
C 220d Wagon
E 220d Wagon
GLC 220d Coupe