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
Related Guides
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.
Scores are calculated from documented issues, repair costs, and failure patterns across thousands of owner reports and technical sources. Learn about our methodology. Always inspect before you buy.