🚗 Classic Fault — Mercedes-Benz W124 (1984–1997)
W124 OM603 diesel injection pump timing drift
💰 Estimated Repair Cost
Up to $200 GBP
Parts and labour estimate
🔧 Tools Required
Dial indicator, injection pump timing tools
📋 Overview
The OM603 six-cylinder diesel injection pump timing drifts with wear, reducing performance and economy.
🩺 Symptoms
- Gradual power loss
- increased black smoke
- harder hot starting
- diesel knock more pronounced
🔍 Possible Causes
- Injection pump timing drift
- worn pump drive
- air in fuel system
🛠️ Diagnosis Steps
Check pump timing with dial indicator. Compare to MB spec. Air bleed fuel system first.
✅ Most Confirmed Fix
Injection pump timing adjustment
80% of users confirm this fix worked (16 reports)
🔗 Other Mercedes-Benz W124 Faults
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