M104
Mercedes-Benz · M104 2.8/3.2 I6
1990–1997
"W124/R129/W140 inline-6. One of Mercedes' most reliable engines. Bulletproof bottom end. Wiring harness biodegrades (uses soy-based insulation). Head gasket solid. 400k+ km possible."
Mileage Risk Timeline
When problems typically appear — enter your mileage to see your risk zone
Known Issues 1
Wiring harness biodegradation
▸Random electrical faults, codes, misfires
Mercedes used soy-based insulation — wiring crumbles with age.
Καλωδίωση σαπίζει — €500-2,000 αντικατάσταση.
Other Mercedes-Benz Engines
Tuning Potential
Limited — NA tuning only
Frequently Asked Questions
Is the Mercedes-Benz M104 reliable?
The Mercedes-Benz M104 scores 85/100 with a verdict of BEST. It has 1 documented issues with total repair costs between €500 and €2,000.
What are the common problems with the M104?
The most common issues are:
- Wiring harness biodegradation — high, repair cost €500–€2,000, 100,000 km–200,000 km
How much does it cost to repair the M104?
Total potential repair costs for all 1 known issues range from €500 to €2,000. The most expensive issue is typically .
What years was the M104 produced?
The Mercedes-Benz M104 was produced from 1990 to 1997. It is a 3199cc I6 petrol na engine.
Verdict and scores are editorial opinions based on aggregated data. Learn about our methodology. Not a substitute for professional inspection.