E46Forum.co.uk

Hello M54 owners,

The BMW M54 engine (found in E46 models like the 325i and 330i) is a smooth straight-six, but it's known for a few common issues, particularly oil consumption and problems with the Crankcase Centilation (CCV) system and DISA valve.

This thread is for UK owners to discuss:

• Oil Consumption: How much oil does your M54 use? What do you consider "normal" vs. excessive? Have you found any effective ways to reduce it (e.g., different oil grades - 5W-30, 5W-40, piston soak, etc.)?
• CCV System (Oil Separator): Symptoms of a failing CCV (e.g., blue smoke, high oil consumption, whistling noises, vacuum issues)? Best replacement kits available in the UK? Is the cold-climate version essential for the UK? DIY difficulty and tips?
• DISA Valve: Telltale signs of a failing DISA valve (rattling, loss of low-end torque, fault codes)? Repair kits vs. new unit? Recommended UK suppliers for parts? DIY guides and experiences.
• VANOS Seals: While we're at it, many M54s suffer from tired VANOS seals. Symptoms and recommended UK kits (e.g., Beisan Systems)?
• Other M54 Specifics: Any other common oil leaks (OFHG, sump gasket) or maintenance tips specific to the M54 in the E46?

Let's share our DIY fixes, recommended parts suppliers in the UK, and approximate costs. If you've successfully tackled these M54 issues, please share your step-by-step guides or links to useful resources.

Please state your E46 model (325i/330i), year, and mileage when sharing your experiences.

Looking forward to your input!