🚗 Classic Fault — BMW (1982–1994)
BMW E30 plastic cooling system expansion tank failure
💰 Estimated Repair Cost
$20 – $70 USD
Parts and labour estimate
🔧 Tools Required
New expansion tank, coolant, hose clips
📋 Overview
The plastic coolant expansion tank becomes brittle with age and cracks suddenly, causing complete and rapid coolant loss.
🩺 Symptoms
Sudden coolant loss. Steam from engine bay. Temperature gauge rises rapidly to maximum.
🔍 Possible Causes
Plastic embrittlement from heat cycling. Age-related material degradation.
🛠️ Diagnosis Steps
Visually inspect tank for cracks or cloudiness. Squeeze tank gently - should not feel brittle.
✅ Most Confirmed Fix
Replace expansion tank proactively on any E30 over 20 years old. Replace all radiator hoses simultaneously.
93% of users confirm this fix worked (45 reports)
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