E46Forum.co.uk

Hi E46 enthusiasts,

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?

Let's Discuss:

• 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?

Let's help each other keep our E46s running cool and reliably on UK roads!

Please mention your E46 model and engine type when contributing.