OM651 (late) vs M104
Side-by-side reliability comparison
Higher reliability score
M104
BEST
85/100
+13 points over OM651 (late)
0
/ 100
ACCEPTABLE
OM651 (late)
Mercedes-Benz
0
/ 100
BEST
M104
Mercedes-Benz
Specifications
OM651 (late)
M104
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
ACCEPTABLE
BEST
Reliability
72
85
Years
2014--2020
1990--1997
Displacement
2143 cc
3199 cc
Layout
I4
I6
Type
Diesel
Petrol Na
Power
136--204 hp
193--231 hp
Known Issues
2
1
Total Risk Cost
€800--€2,200
€500--€2,000
Character
OM651 (late)
"Post-2014: updated injectors + pump. Much improved. Highway excellent."
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."
Issues Comparison
OM651 (late) 2
▲ HIGH
DPF blockage — city driving concern
● MODERATE
EGR valve fouling (post-2014)
M104 1
▲ HIGH
Wiring harness biodegradation
Models
OM651 (late) 10
M104 0
No models listed.