ok so i decided to take apart my disa just to see what it looked like inside since literally the omly thing that could produce the issue ive had was it, ok so when i pulled disa out of manifold the lever thingy moved both ways completly freely, and as far as i know thats no right isnt it supposed to be held by spring or something at least one way? if i remeber right i thought it was supposed to stay like this -- rather than | or am i wrong and when pulling it off car its ok for it to move completely freely like that?

 

What year car do you have. In the E60s the DISAs are a common issue. If you find it malfunctioning changed it and pay attention to the vacuum lines for cracks

 

i have a 04 525i wit m54 engine, i just clicked over 150k miles on it as well. my two observations are that the other day i tried unplugging disa and engine sounded no different, not at idle or when i took it for a drive down street, it actually made no difference at all if it was plugged in or not the car still had the same issues. then today i decided to take it off car and see if i noticed anything, and soon as it came out of manifold i noticed that the flapper thing was literally just hanging there freely, i could move it one way or the other with no force at all, if i remeber right the flapper should stay in middle moving with a lil force but it shouldnt just freely flip around right? i hope not cuz i ordered disa already cuz along with these things the o-rings also looked bad so im sure they need to be changed.