OM668
Mercedes-Benz · OM668 1.7 Diesel
1998–2004
"W168 A-Class. Same era as M166 petrol. Injector issues. Head gasket concerns. Turbo failure on higher-output version. Not Mercedes' best diesel. Better alternatives exist."
Mileage Risk Timeline
When problems typically appear — enter your mileage to see your risk zone
Known Issues 2
Head gasket failure
▸Coolant loss, smoke
W168 diesel head gasket known weak.
Φλάντζα W168 diesel — €500-1,200.
Injector failure
▸Rough idle, smoke
Early CDI injectors.
Μπεκ — €300-800.
Models with OM668 2
Other Mercedes-Benz Engines
Tuning Potential
Minimal
Frequently Asked Questions
Is the Mercedes-Benz OM668 reliable?
The Mercedes-Benz OM668 scores 58/100 with a verdict of CAUTION. It has 2 documented issues with total repair costs between €800 and €2,000.
What are the common problems with the OM668?
The most common issues are:
- Head gasket failure — high, repair cost €500–€1,200, 80,000 km–150,000 km
- Injector failure — moderate, repair cost €300–€800, 80,000 km–150,000 km
What cars use the Mercedes-Benz OM668?
How much does it cost to repair the OM668?
Total potential repair costs for all 2 known issues range from €800 to €2,000. The most expensive issue is typically .
What years was the OM668 produced?
The Mercedes-Benz OM668 was produced from 1998 to 2004. It is a 1689cc I4 diesel engine.
Verdict and scores are editorial opinions based on aggregated data. Learn about our methodology. Not a substitute for professional inspection.