Higher reliability score
M104 BEST 85/100
+47 points over OM651 (early)
0 / 100
AVOID OM651 (early) Mercedes-Benz
0 / 100
BEST M104 Mercedes-Benz

Specifications

OM651 (early)
M104
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
AVOID
BEST
Reliability
38
85
Years
2008--2014
1990--1997
Displacement
2143 cc
3199 cc
Layout
I4
I6
Type
Diesel
Petrol Na
Power
136--204 hp
193--231 hp
Known Issues
3
1
Total Risk Cost
€2,700--€7,200
€500--€2,000

Character

OM651 (early)

"Pre-2014: injectors, timing chain, DPF. Hard to work on."

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 (early) 3

◆ CRITICAL
Piezoelectric injector failure (pre-2014) €1,200--€3,500 60,000 km--130,000 km
◆ CRITICAL
Timing chain stretch (pre-2014) €1,000--€2,500 80,000 km--150,000 km
▲ HIGH
DPF + EGR fouling (city use) €500--€1,200 60,000 km--120,000 km

M104 1

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

Models

Full OM651 (early) Report Full M104 Report