OM651 (early)
Mercedes-Benz · 2.1L Diesel I4
2008–2014
"Pre-2014: injectors, timing chain, DPF. Hard to work on."
Mileage Risk Timeline
When problems typically appear — enter your mileage to see your risk zone
Known Issues 3
Piezoelectric injector failure (pre-2014)
▸Rough idle, misfires, smoke, loss of power, P030X codes
Pre-2014 OM651 injectors fail prematurely. Expensive replacement. The primary reason to avoid pre-2014.
Pre-2014 OM651 purchase: verify injector status. Budget €1,200-3,500 for full set if needed.
Timing chain stretch (pre-2014)
▸Cold start rattle, check engine light, timing issues
Pre-2014 OM651 also had timing chain concerns on top of injector issues.
Two critical issues on pre-2014 = AVOID verdict fully justified. Post-2014 much improved.
DPF + EGR fouling (city use)
▸DPF warning, limp mode, rough idle
Standard diesel DPF/EGR issues compounded by pre-2014 engine unreliability.
Athens city use makes this worse. Pre-2014 OM651 is the wrong choice for Greek city driving.
Models with OM651 (early) 34
Other Mercedes-Benz Engines
Tuning Potential
Moderate but risky
Frequently Asked Questions
Is the Mercedes-Benz OM651 (early) reliable?
The Mercedes-Benz OM651 (early) scores 38/100 with a verdict of AVOID. It has 3 documented issues with total repair costs between €2,700 and €7,200.
What are the common problems with the OM651 (early)?
The most common issues are:
- Piezoelectric injector failure (pre-2014) — critical, repair cost €1,200–€3,500, 60,000 km–130,000 km
- Timing chain stretch (pre-2014) — critical, repair cost €1,000–€2,500, 80,000 km–150,000 km
- DPF + EGR fouling (city use) — high, repair cost €500–€1,200, 60,000 km–120,000 km
What cars use the Mercedes-Benz OM651 (early)?
How much does it cost to repair the OM651 (early)?
Total potential repair costs for all 3 known issues range from €2,700 to €7,200. The most expensive issue is typically .
What years was the OM651 (early) produced?
The Mercedes-Benz OM651 (early) was produced from 2008 to 2014. It is a 2143cc I4 diesel engine.
Verdict and scores are editorial opinions based on aggregated data. Learn about our methodology. Not a substitute for professional inspection.