M54 DISA fix
 

I might have posted this before but when I bought the X5 it had about 192K and the DISA was rattling apart, I think the pin had even come out. I ordered a repair kit but did a repair in the meantime by putting a brass sleeve/bushing on the stub shaft end and siliconing the hex drive part. I never did install the kit and just now had it apart and after many years (now 463K km) it is still %110! :)

It might have been a piece of heat shrink instead of the brass sleeve, I should have put my glasses on and had a better look, but either way better than new or kit! ;)

Wow, you must not rev it above 3000 RPMs. Does the DISA valve open above 3000 RPMs?
Mine is showing signs of oil fume seep. It did have a preventative maintenance kit installed on it a while back. It may be time to go new.

I think the main problem originally is that it wears out/falls apart from rattling not so much wear from operating. Reducing the clearance on the stub end (not sure how much because I never compared it to a new one) AND I think even more important by having no clearance on the drive end but still some flex with the silicon makes a huge improvement. ;)

I finally got to doing a smoke test yesterday. The disa o-ring is leaking bad. I'll have to take it off cover that up and retest. The large diameter short vacuum line there to the CCV is also leaking. The fuel trim codes have progressed to system too lean codes.

I'm looking at this disa thing and I have all the symptoms of a bad one. Is this the repair kit you went with? https://germanautosolutions.com/gas-...-oem-bmw-disa/

I think I'll do that over buying a cheap one. I'm hopeful just that and a new vac line is all she needs.

I don't know where I got the kit from but I never used it. The "patch up" job I did worked perfectly and has proven itself as likely permanent because it addresses the problems better than any kit.

the G.A.S. repair kit for DISA valve is worth the cost
 

I've been looking for the cause of my lean fuel trims for over 3 years now, smoke-testing and all, with no success (maybe the used Siemens MAF that X5chemist sent me will tell me something... when/if the bad piriformis/peroneal tendontis/sciatica in my right leg lets up enough for me to drive).

One of the early things I tried was inspecting the DISA valve, which was rattling. I'd read that the pivot pin inside might fall into a cylinder and hole a piston (I think bimmerbreaker said it wasn't true), so I bought the $65 G.A.S. repair kit, since it was surely better than $10 kits on Amazon.

It was easy to repair, and I used the improved O-ring, too, so it should be good for many years. P.S. it wasn't ever leaking, but now I wasn't worrying about it either.

Yeah I'm debating on the repair kit or just getting the new one from FCP Euro. Junk aftermarket, but free-ish replacement.

Regarding sciatica etc. I was having all that a few years ago, and the one physical therapist explained to me that my head is forward. And that I need to make a constant effort to keep it way back over my shoulders, both sitting and standing. After a few weeks of that everything cleared up and I quit going to the appointments, been fine since.

Mine has that kit and tank cap. I had to use sandpaper on the flap round pivot points. The main shaft was too tight. It would not open without force. I sanded it down until it moved freely. It has been working fine for a good while.