E39 rough idle

[satumashirt611]

had a few minutes so changed the plugs and no difference.barely any power now and cuts out.next to check as dod said is the hoses for cracks or wear and disconnect the maf to see any difference..
very worried about things..would a diagnostic unit show up whats up even if it was cracked hose.might know someone who can check but he may be away.

You need something you can spray on the hoses so you can spot air being released.

not easy with the gale force winds and heavy rain today....

[GERMANIKS]

I'd still bet its the vacume hoses betweeh the Air flow meter and the throttle body.

well just disconnected airflow meter and car runs perfect..why is it running good with this unplugged.no cutting out at all but when I plug it back in straight away cuts out....

Thats it that's you sorted. Just get a new one.
Runs fine for now as it is no longer sending crazy info to the engine management. But you still need to get it sorted asap.

I think the maf-shop.com is a good bit cheaper but some managed to replace the sensor only from VAG dealer as it is the same one, as bmw does not sell the sensor on its own.