🚗 Classic Fault — Volkswagen (1983–1992)
Golf Mk2 coolant temperature sender giving wrong signal
💰 Estimated Repair Cost
$8 – $25 GBP
Parts and labour estimate
🔧 Tools Required
Multimeter
📋 Overview
The single-pin coolant temp sender for the ECU ages and gives incorrect signals, causing rich running and poor economy.
🩺 Symptoms
- Black smoke
- poor fuel economy
- engine takes too long to warm up according to gauge
- rough idle when warm
🔍 Possible Causes
- Failed coolant temp sender
- incorrect sender fitted (gauge sender vs ECU sender are different)
- air in cooling system
🛠️ Diagnosis Steps
Check sender resistance with engine cold and warm — compare to VW spec chart. Note: gauge and ECU use separate senders
✅ Most Confirmed Fix
Coolant temp sender replacement
89% of users confirm this fix worked (52 reports)
🩺 Related Symptoms
🔗 Other Volkswagen Faults
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