Symptoms of a faulty DISA flap?

[Aebous]

I didn't notice a difference after the DISA was replaced. Of course I was really tired so probably not paying attention.

[cj10jeeper]

Hey Shipkiller - no suprise - I found that one of the flexis after the airbox had not seated properly. Redid it correclty and the whistle vanished.

Teach me not to do things quickly in fading light (or at least put the floodlights on in the garage)

[Mr Whippy]

I think I'm off to buy this part tomorrow, or at least order it.

In the name of testing (because I think it will make some difference), I'll do an acceleration test in 3rd through the revs side by side with old vs new (swap during test)

Lets see how more filled in the torque becomes

Before fyi:

[Mr Whippy]

Ooof, £114 for a new DISA flap thingy from BMW.

Picking it up on Wednesday along with my new brake vacuum pipe (£21), the old one had collapsed... so a few little jobs to do

Really looking forward to seeing how secure it is. The parts guy went "ahh (knowingly), one of those" when I told him I wanted a new DISA flap actuator, so clearly they get a few with issues!

Dave

[Mr Whippy]

Just got my new one today.

Solid as a rock in every way my old one wasn't.

No give in the door in the open or closed positions when holding the crank arm in place, no lateral or longitudinal movement about the pin. I'll have to see what it is like after it's first month in place.

Will try do the before/after test this evening

Cheers

Dave

[EdButler]

Bump!

Any developments on this Mr. Whippy??

[Mr Whippy]

I haven't undertaken any empirical testing, but purely on perception the engine feels less confused at part throttle openings. The solidness of instant output that is clear at higher throttle inputs seems to be more apparent now at smaller ones, quicker.
The rattle is totally gone now too, much quieter inside and out at idle and when on the move (was surprising how loud it was!)

If it's rattling I'd say it's due a swap, and it's easy to tell at idle if it's rattling by simply unplugging it. It can't be good to have it rattling around as much as it does inside there. Fatigue will finally catch up with components and do damage, and fatigue wear must be off the scale with it rattling around as much and as fast as it clearly was!

Dave

[nadaclue]

Thank you, thank you, thank you!

This rattling/clicking noise has been progressively getting worse and noisier over the past 2 weeks and has started to make me paranoid. Today I did an oil change followed by an Italian tune-up but it was still there. Seemed to be located closer to the intake manifold than the head, almost sounded like extremely loud and poorly timed injectors so I started searching for common injector issues on the M54 but couldn't find much. So I started going through the "problems" forum hear, and found this thread. The part that made me really suspicious it was the DISA was the fact that the noise went away at higher RPM's. I just figured at the time it was being drowned out by the increased engine noise.

I went out to the garage, started the Z4 and was greeted by the incessant "ticking". Unplugged the DISA and holy crap it went away!

So again, thank you everybody. Saved me a trip to the shop and I can rest in peace knowing is a relatively inexpensive item and not my head or injectors.

Now the question is, can I drive it with the DISA unplugged for the next couple of days until I get a new one?

For the record, 2003 Z4 w/ 42k miles.

[Andrew D]

Can anyone post the part number for the replacement flap assembly?

I note on RealOEM.com that there are two entries for this item, one (part number 11617502275) ended 04/2004 and another still current (11617544805). Maybe a part redesign on the sly?