I have a '97 328is stick and there is a cylindrical device about 8"-10" in diameter in the back left corner of the engine bay which sounds like a vacuum cleaner on high. It stays on first thing in the day for about 2-3 minutes. I don't remember hearing it in the past. I disconnected it and the car seems to work fine, but that's a bit naive and I'd rather figure out what the actual problem is. What is this thing, and do I need it? Its starting to grind a bit as well, like the bearing is worn/wobbling. I've always needed to vacuum my car more often, can I re-purpose it? Thanks
Sounds like the secondary air pump. They do tend to make a bit of noise. Sounds like a CEL is in your future.
Ah Yes - I looked it up on BavAuto, and that's the thing. At $400, I might be looking up the local junk yard... Thanks for the pointer.
But it dawns on me - is it running long due to something downstream telling it to, and this device is actually okay? Hmmm... A fault code might actually be helpful about now.
Autohausaz.com has them for around $300 http://www.autohausaz.com/search/product.aspx?sid=vg0g5eamqj2tsn45vlhiqk45&makeid=800003@BMW&modelid=1011991@328IS&year=1997&cid=19@Emission%20System&gid=4920@Air%20Pump/Smog%20Pump A new one might be cheaper than buying another one that's also on its last legs. Likely being the original unit, for $400 that car has likely gotten its money's worth out of it after 14 years of service. Or you might be able to disassemble it, clean it and get a little more use out of it.
Be sure you replace the vacuum-controlled valve mounted above the exhaust headers. Failure of this valve is most often the cause of air pump failure. Replacing only the pump will lead to its early failure.
The pump is supposed to run on cold startup for a couple of minutes. It will make some noise, but it sounds like yours is on the way out. 217 is correct. If the secondary air valve leaks back into the blower, the bearings will die a quick death. Disassembly is out of the question. I have tried it. If it dies, the CEL will go on and stay on since it is part of the emissions system. You will need to replce it soon.
