N52 Small DISA rubber perished - Need advice on replacement

Hi guys,

I've got an ongoing thread (https://z4-forum.com/forum/viewtopic.php?f=3&t=110050) about issues with my N52 engined E91. I finally bit the bullet and decided to renew the CCV system, so today I got the intake manifold off (ballache). I had a feeling there was going to be an issue with the inner DISA valve and to my surprise, the flap is rigid and I suspect it works fine, but the rubber seal on the unit has broken away in several places (pictures below).

I am wondering if anyone know where I can source one other than a dealer, as I think they are about £250. Seems it's really difficult to find OE quality parts in the UK. Any advice would be greatly appreciated, as the car will be off the road until I can find a replacement unit!

Thanks

How's this for you? https://www.autodoc.co.uk/metzger/12821014

I've used autodoc multiple times for beemer and audi parts over the past couple of years without any complaints thus far.

PinkPineapple44 said:

How's this for you? https://www.autodoc.co.uk/metzger/12821014

I've used autodoc multiple times for beemer and audi parts over the past couple of years without any complaints thus far.

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I have to say, I wondered about that site when looking for CCV parts, but encountered pretty mixed reviews. I also looked at it for the DISA but I wasn't sure about the quality of the various brands. As such, I ended up befriending a guy from Sytner near me and got a bit of a discount. £238 for the small DISA, which is ludicrous, but I can get it tomorrow morning and can be sure of the quality.

Out of interest, I don't suppose you have any experience of the quality of parts made by the manufacturer in your link? For future when something else breaks haha.

Wow. I did a how-to on how to inspect your disa on an n52 a few years ago now and mine was fine. Lots of people have used it since, definitely worth posting a link to this thread as an update so people are not lulled into a false sense of security and decide not to check it

I’ll do it now, good news you’ve caught it... I wonder where those rubber bits are now though :?

Even if the rubber has perished slightly and leaking a small amount of air, i’m not convinced it would have any impact on performance or smooth running. You have to remember that the only purpose of these valves is to alter the effective inlet manifold lenght to aid induction at certain rpms. Its really more an optimisation than a critical function.

propaintballa said:

PinkPineapple44 said:

How's this for you? https://www.autodoc.co.uk/metzger/12821014

I've used autodoc multiple times for beemer and audi parts over the past couple of years without any complaints thus far.

Click to expand...

I have to say, I wondered about that site when looking for CCV parts, but encountered pretty mixed reviews. I also looked at it for the DISA but I wasn't sure about the quality of the various brands. As such, I ended up befriending a guy from Sytner near me and got a bit of a discount. £238 for the small DISA, which is ludicrous, but I can get it tomorrow morning and can be sure of the quality.

Out of interest, I don't suppose you have any experience of the quality of parts made by the manufacturer in your link? For future when something else breaks haha.

Click to expand...

No sorry, I haven't used that specific brand. I tend to stick with the higher quality brands such as Bosch, Mann etc but have used a couple I had never heard of before. Did some research first before biting the bullet just to make sure they weren't total trash though!

For the small one it might be worth a punt with an aftermarket part as it is accessible with the manifold installed, unlike the inner one.

Holy crap wow I have the same exact issue right now!
I'm replacing my CCV with the whole kit from FCPEuro and when I took my intake manifold off there was a little bit of oil.
I cleaned everything and took off both DISA Valve.
The bigger one by the throttle body was so bad the flap was dangling. The inner smaller one behind the manifold look exactly like yours.
It was stiff but some of the rubber look like it came off but it look exactly like your pictures.
I'm buying the bigger DISA Vavle ESK 001 for sure but I'm debating on the smaller one.
Did you end up getting a new one or just stuck it back in and did it make a difference?

There exists a test option in IN.PA for these flaps. Replacement decisions should be also taken on test results, not only by "feelings".
Take it off and check the electrical movement of the flaps. Mine stucked while closing, opening was fine. Sometimes you can find a documented fault code.

RobbiZ4 said:

There exists a test option in IN.PA for these flaps. Replacement decisions should be also taken on test results, not only by "feelings".
Take it off and check the electrical movement of the flaps. Mine stucked while closing, opening was fine. Sometimes you can find a documented fault code.

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Aw bummer, I should done that test when it was still on the car. I do have IN.PA installed on my computer in the garage but everything is already off on the work bench to replace the new BMW CCV. I did ran a test and everything was clear and no codes prior to the removal. It's only a tiny idle fluctuation(100-200 rpm idk needle moved a little) during start up for maybe 5 seconds and the sluggishness during around 3-5k rpm. I'm about to buy the larger OEM BMW DISA valve but at this point might just have to get the smaller one too. With all this Coronavirus and working from home I have more time to work on this car anyways.

I’m not entirely sure if the INPA test tells you anything meaningful, I don’t really see how it can report on the condition of the rubber seal at all...or even if the flap is moving cleanly or not. I suspect the best it can do is report that the servo coil is there electrically and draws the expected current.

Bear in mind the post I made above.

I wrote a bunch of stuff earlier but it all got wipe when I stepped out for a little bit, had to log back in. :x
Anyways I basically went ahead and did the test and it appears to be functioning but not perfect. I order 2 new units.
[youtube]https://youtu.be/EiStxboZCzM[/youtube]

mcentral said:

I wrote a bunch of stuff earlier but it all got wipe when I stepped out for a little bit, had to log back in. :x
Anyways I basically went ahead and did the test and it appears to be functioning but not perfect. I order 2 new units.
[youtube]https://youtu.be/EiStxboZCzM[/youtube]

Click to expand...

Whoa.... your large DISA looks totally fubar’d! What symptoms were you getting? Also, were you expecting the small disa to fully close?

Hi,

I had a z4 until a few years ago but we had a kid so I have an E61 530i now I always had good experience/help on this forum and we have the same motor...

Soooo...

I was wondering if anyone had any experience with the cheap amazon/ebay DISA valves?

I have a silvertop N52B30 with the three stage manifold and both my valves are seized, they won't rotate when testing in ISTA+

I split one open with a blade and it was absolutely full of oil, the servo itself works when I plug in the half of the unit with the motor/control board in it and run the test in ISTA+

So I'm in a quandary as to whether I repair them using the i6 repair kits or to try cheap "oem" ones. For the mileage on the car I will not be buying new from bmw and ones from a breakers may also fail for £120 odd each.

I'm leaning towards repairing myself but thought I'd ask in case anyone has a positive experience of the Chinese copies...

Cheers all, Dean

If your DISA is full of oil then you have a problem with the crankcase ventilation system (CCV). You need to get that sorted first before fitting a new DISA otherwise you will just end up in same position in a few months time.

Hi,

Thanks for the advice, yeah i was working on the assumption that the CCV was gone as i have various oil leaks from the valve cover and the engine/underside of the car is plastered in engine oil.

So I'd taken the car off the road to do the valve cover gasket, clean the engine and replace the CCV, so 2 seized oil-filled DISA valves has double-confirmed my suspicions!

I've ordered one each of these to try and repair the valves :-

https://www.i6automotive.co.uk/aluminium-repair-kit-disa-intake-aduster-bmw-engine-n51-n52-n52n-n52k-large-v.html
https://www.i6automotive.co.uk/aluminium-repair-kit-disa-intake-aduster-bmw-engine-n51-n52-n52n-n52k-small-v.html

I'm struggling to find the 95% formic acid that is used in manufacture and recommended for rebonding the PA66-GF30 (basically carbon fibre reiinforced nylon) that the casements are made from. The formic acid needs to be 95% strength to work as it basically melts the plastic together as bonding polyamides can be difficult apparently.

Just for clarity i'm no plastics expert this is just what i've gleaned from googling over the past few days

So I'm currently debating this polyamide compatible 2K epoxy from Araldite...

https://uk.rs-online.com/web/p/products/3888926/

It's not cheap but i dont want DISA valves falling apart in my intake manifold, because :-
a-I can't be arsed to take this apart again its been a ballache..
b-bits getting sucked into pistons = not good...

I'll report back and create a new DISA rebuild thread when i'm done in case it helps others in the future.

Cheers,

Dean

P.S. And why the f*** BMW didn't make these servicable with screws in the casements is utter utter b******* and IMHO purely down to parts marketing and a money grab. The E46 DISA has screws in it, and £250-300 for a piece of plastic with a motor in it is frankly taking the p***. I thought £650 for a water pump was bad enough but at least you can see the value in the lifetime/engineering/manufacture of them, now I've had these DISA valves open you can see they're basically wear/service items and should be priced accordingly. Rant over!