🚗 Classic Fault — Mercedes-Benz W124 (1984–1997)
W124 E320 M104 head gasket failure at high mileage
💰 Estimated Repair Cost
$250 – $700 GBP
Parts and labour estimate
🔧 Tools Required
Combustion leak tester, torque wrench
📋 Overview
The M104 24-valve engine can suffer head gasket failure between cylinders at high mileage, particularly if previously overheated.
🩺 Symptoms
- Coolant loss
- white exhaust smoke
- rough running
- coolant in oil
- overheating
🔍 Possible Causes
- Blown head gasket
- warped head from previous overheat
- cracked head
🛠️ Diagnosis Steps
Combustion leak test in coolant. Check oil for emulsification. Compression test.
✅ Most Confirmed Fix
Head gasket replacement with head skim
77% of users confirm this fix worked (21 reports)
🔗 Other Mercedes-Benz W124 Faults
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