BMW E46 328ci

[ChrisMills4378]

I’m new to this forum and was hoping someone could help me out with a question regarding a component under the bonnet of a BMW E46 328ci. I Have been looking at one of these for sale and when I opened the bonnet to check out the engine (which had just been started) this component was making a noise that sounded like an electric motor running at high speed and it was also making a vacuum popping sound. The sounds ceased after a couple of minutes but it didn’t sound normal. The item in question is about 3.5 inches in diameter and positioned on the right hand side between the windscreen washer bottle the suspension tower and the engine. I have looked at some 330’s as well and cannot see this component. Is this an item to look out for? Which is the better model in everyone’s opinion?

[essayer]

It’s the secondary air valve, used to mix ambient air with the exhaust gases during a cold start. IIRC they make a bit of noise but this is normal, maybe check the hoses if it’s bad. if it’s not working properly the car should show an emissions fault

[helix402]

It’s the aux pump. It can be removed from a 328i/ci and binned. Buy the exhaust manifold blanking plate from an M54. No emissions light will be lit.

[ChrisMills4378]

Thanks for your help guys. Cheers

[Touring442]

helix402 said:

It’s the aux pump. It can be removed from a 328i/ci and binned. Buy the exhaust manifold blanking plate from an M54. No emissions light will be lit.

I had one on a 323i - I removed and gave it the distance test. It passed!