OM651 (early) vs OM648
Side-by-side reliability comparison
Higher reliability score
OM648
BEST
90/100
+52 points over OM651 (early)
0
/ 100
AVOID
OM651 (early)
Mercedes-Benz
0
/ 100
BEST
OM648
Mercedes-Benz
Specifications
OM651 (early)
OM648
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
AVOID
BEST
Reliability
38
90
Years
2008--2014
2002--2006
Displacement
2143 cc
3222 cc
Layout
I4
I6
Type
Diesel
Diesel
Power
136--204 hp
204 hp
Known Issues
3
2
Total Risk Cost
€2,700--€7,200
€450--€1,100
Character
OM651 (early)
"Pre-2014: injectors, timing chain, DPF. Hard to work on."
OM648
"Modern OM606 successor. Excellent highway cruiser. Strong torque."
Issues Comparison
OM651 (early) 3
◆ CRITICAL
Piezoelectric injector failure (pre-2014)
◆ CRITICAL
Timing chain stretch (pre-2014)
▲ HIGH
DPF + EGR fouling (city use)
OM648 2
● MODERATE
EGR valve fouling (city use)
○ MINOR
Glow plugs + injector seals