🚗 Classic Fault — Mercedes-Benz (1976–1985)
W123 200D OM615 glow plug failure — hard cold start
💰 Estimated Repair Cost
$40 – $130 USD
Parts and labour estimate
🔧 Tools Required
Multimeter, glow plug socket, torque wrench
📋 Overview
One or more glow plugs fail in the W123 diesel engine making cold starting in temperatures below 5C difficult or impossible.
🩺 Symptoms
Difficulty starting when cold. White smoke on startup. Engine cranks for extended periods before firing.
🔍 Possible Causes
Glow plug element burnout. Failed glow plug relay or controller. Corroded connections.
🛠️ Diagnosis Steps
Test each glow plug resistance — should read 0.5-2 ohms. A reading of zero or infinite indicates failure.
✅ Most Confirmed Fix
Replace failed plugs with Beru or Bosch quality units. Test relay if multiple plugs fail simultaneously.
86% of users confirm this fix worked (34 reports)
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