🚗 Classic Fault — Mercedes-Benz W115 (1968–1976)
Ignition timing too retarded — flat power
💰 Estimated Repair Cost
Up to $20 USD
Parts and labour estimate
🔧 Tools Required
Timing light, vacuum advance plug
📋 Overview
Incorrect ignition timing is one of the most common causes of poor performance. Retarded timing causes flat power delivery, overheating, and poor fuel economy.
🩺 Symptoms
- Flat power
- overheating
- poor fuel economy
- engine runs hot
- exhaust note sounds dull
🔍 Possible Causes
- Incorrect timing set during service
- timing marks obscured
- slipped rotor pin
🛠️ Diagnosis Steps
Clean timing marks. Set timing with light to 10 degrees BTDC at idle with vacuum advance disconnected.
✅ Most Confirmed Fix
Set timing to 10 degrees BTDC. Check vacuum advance operation.
85% of users confirm this fix worked (31 reports)
🔗 Other Mercedes-Benz W115 Faults
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