Test valve Disa with ignition key.

[520i E60]

https://youtu.be/nxVSLBsExVc

[bmwdirtracer]

Sigh.

Does it rattle? You know you need a smoke test now that you removed that, right?

The DISA doen't usually fail by failing to move -- it usually fails by rattling itself to pieces, then coming apart, and dropping its pivot pins into some cylinder. Diagnosing a DISA valve without seeing whether it rattles or leaks smoke is just silly.

Do you even HAVE a smoke machine?

Perhaps you'd like to read a little about DISA failure, before you attempt to educate us again:

http://www.germanautosolutions.com/b...a_products.php