I was directed to this forum from another Bimmer owner. I have a 2008 535XI that is throwing a Engine Malfunction reduced power error. I took it into the shop and they found a vacuum hose that was disconnected and reconnected it. They mentioned that the error thrown was 30FF and have me monitoring until the error becomes more prevalent before they will do anything. Is there something that I can do in the meantime to fix this my self. With directions I can do most things.

Operational but concerned in Seattle

 

That code is for a vacuum hose disconnected or open. If they put it back the code should be gone if it's still there they didn't fix it and you still have an issue with open vacuum on one of your lines.

If you still have the code then check your lines and change the one that is bad. Ensure the nipples/canisters they are attached do not have a crack in them. That's all we can advise you to do.

 

That code typically means a boost leak. It ends up being quite common on N54s and could be bad wastegates on the turbos (do you hear a rattling sound at idle that sounds like a can of nails?) or a bad connection on a charge pipe. I would look for those first. My wastegates were failing and if I punched the throttle when I was at around 2400 rpm it would set that code. I grew up in Renton and would love to help you out if I was there (parents are still there) were it not for this virus...

I do all work myself these days but did have success at Strictly BMW when I lived down there.

 

You say you took it into the shop and they found a vacuum hose that was disconnected and reconnected it.

How did the hose get disconnected?

Is the hose connection broken?

That could never happen with any of my hoses unless the plastic end was broken. Best to replace that hose.