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BMW Radiator Types and When to Replace
BMW Radiator Types and When to Replace
Radiator Construction
BMW radiators use aluminum cores with plastic end tanks. The plastic tanks are the weak point — they become brittle with age and heat cycling.
When to Replace
Signs of Radiator Failure
- Visible cracks in plastic end tanks
- Coolant weeping from tank-to-core seam
- Discoloration — brown/yellow staining on tanks indicates heat damage
- Coolant loss with no other visible leak
- Overheating — partially clogged radiator reduces cooling capacity
Preventive Replacement
- E46: Replace at 100,000-150,000 km as part of cooling system refresh
- E90: Replace if showing any signs of age
- F30+: More durable but still inspect at 100,000+ km
OEM vs Aftermarket
| Brand | Type | Quality | Price |
|---|---|---|---|
| Behr/Mahle | OEM supplier | Excellent | €200-400 |
| Nissens | Aftermarket | Very Good | €150-300 |
| CSF | Performance | Excellent | €300-500 |
| Mishimoto | Performance | Good | €250-450 |
Performance Radiators
For tuned or track cars, upgraded radiators offer:
- All-aluminum construction — no plastic to crack
- Larger core — more cooling capacity
- Higher fin density — better heat transfer
- Direct fit — bolt-in replacement
Popular for N54/B58: CSF, Mishimoto, Wagner
Maintenance
- Flush coolant every 2 years
- Inspect radiator during every oil change
- Check for debris blocking airflow (bugs, leaves)
- Ensure radiator fans are functioning properly
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