🚗 Classic Fault — Volkswagen (1983–1992)
Golf Mk2 idle control valve failure
💰 Estimated Repair Cost
$25 – $80 GBP
Parts and labour estimate
🔧 Tools Required
Carb cleaner, multimeter
📋 Overview
The auxiliary air valve or idle stabiliser valve fails, causing erratic idle on injection models. Very common on high-mileage Mk2s.
🩺 Symptoms
- Hunting idle between 500-1500rpm
- engine stalls at junctions
- idle improves when valve unplugged
🔍 Possible Causes
- Failed idle stabiliser valve
- dirty throttle body bypass port
- air leak past throttle plate
🛠️ Diagnosis Steps
- Unplug idle valve — if idle stabilises the valve is at fault. Clean with carb cleaner and test
- replace if faulty
✅ Most Confirmed Fix
Idle valve replacement or throttle body clean
84% of users confirm this fix worked (47 reports)
🩺 Related Symptoms
🔗 Other Volkswagen Faults
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