The cooling system is arguably the Achilles' heel of the BMW E46. Preventative maintenance is key to avoiding catastrophic engine damage from overheating. This thread is to compile a comprehensive UK parts list and DIY guide for a full E46 cooling system overhaul.
Whether you have a petrol (316i, 318i, 320i, 323i, 325i, 328i, 330i) or diesel (318d, 320d, 330d), your cooling system needs love!
Key Components for Overhaul:
- Expansion Tank (Header Tank): Prone to cracking. Recommended brands (Meyle HD, Behr, Genuine BMW)?
- Water Pump: Plastic vs. metal impeller? Which brands are reliable?
- Thermostat: Include housing? Recommended temperature rating?
- Radiator Hoses: Top, bottom, and any smaller breather hoses.
- Radiator: When is replacement necessary?
- Coolant Level Sensor: Often fails.
- Fan Clutch (if applicable) / Electric Fan: Testing and replacement.
- Serpentine Belts & Tensioners/Pulleys: Good to do at the same time.
- Coolant: Which type is correct for the E46 (e.g., BMW Blue G48)? How much is needed?
- What's your recommended interval for a cooling system refresh (mileage/years)?
- Share your preferred UK suppliers for quality cooling system parts (e.g., Euro Car Parts, GSF, BMW specialists, eBay sellers).
- Any DIY tips, tricks, or special tools needed for the job?
- Links to good video guides or write-ups?
- Approximate cost for a DIY overhaul using good quality parts in the UK?
Please mention your E46 model and engine type when contributing.
