M166
Mercedes-Benz · M166 A-Class 1.4/1.6
1997–2004
"W168 A-Class. Infamous moose test rollover era. Engine itself is adequate but head gasket failures common. Oil leaks. Not a strong Mercedes engine. Better to look at M271 successor."
Mileage Risk Timeline
When problems typically appear — enter your mileage to see your risk zone
Known Issues 1
Head gasket failure
▸Overheating, coolant loss
A-Class M166 head gasket is a known weak point.
Φλάντζα κεφαλής W168 — κλασικό. €500-1,200.
Models with M166 3
Related Guides
Other Mercedes-Benz Engines
Tuning Potential
None
Frequently Asked Questions
Is the Mercedes-Benz M166 reliable?
The Mercedes-Benz M166 scores 55/100 with a verdict of CAUTION. It has 1 documented issues with total repair costs between €500 and €1,200.
What are the common problems with the M166?
The most common issues are:
- Head gasket failure — high, repair cost €500–€1,200, 60,000 km–120,000 km
What cars use the Mercedes-Benz M166?
How much does it cost to repair the M166?
Total potential repair costs for all 1 known issues range from €500 to €1,200. The most expensive issue is typically .
What years was the M166 produced?
The Mercedes-Benz M166 was produced from 1997 to 2004. It is a 1598cc I4 petrol na 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.