OM651 (early) vs OM606
Side-by-side reliability comparison
Higher reliability score
OM606
BEST
96/100
+58 points over OM651 (early)
0
/ 100
AVOID
OM651 (early)
Mercedes-Benz
0
/ 100
BEST
OM606
Mercedes-Benz
Specifications
OM651 (early)
OM606
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
AVOID
BEST
Reliability
38
96
Years
2008--2014
1993--2001
Displacement
2143 cc
2996 cc
Layout
I4
I6
Type
Diesel
Diesel
Power
136--204 hp
134--174 hp
Known Issues
3
2
Total Risk Cost
€2,700--€7,200
€280--€700
Character
OM651 (early)
"Pre-2014: injectors, timing chain, DPF. Hard to work on."
OM606
"Legendary. 500k+ miles documented. Tunable to 500hp. One of most reliable engines ever."
Issues Comparison
OM651 (early) 3
◆ CRITICAL
Piezoelectric injector failure (pre-2014)
◆ CRITICAL
Timing chain stretch (pre-2014)
▲ HIGH
DPF + EGR fouling (city use)
OM606 2
○ MINOR
Glow plug failure (only meaningful issue)
○ MINOR
Injection pump seal wear (age-related)