DISA Valve repair kit

Originally Posted by BikesStillRule

Thanks doru for posting that application list, I need to give you a commision.

It also fits p/n 11617502275 which is superseded by the above number. The p/n's are stamped on the housing but the unit needs to be removed to read the number.

As soon as I can I will get my hands on the version for the 2.5L models and the M52tu models. Maybe we will get lucky and the internals will be the same. If not I will definitely make a version for the 2.5L and possibly the M52tu.

Does anyone have an old unit in their possession that would be willing to send it to me, it would save me $275.00 ea.

The new unit you made for the 3.0L M54 looks identical to mine (2.5L)...

This weekend I can try to take some measurements of mine, maybe the difference doesn't affect the flap

Here are the preliminary install instructions. All feedback welcome.


What comes in the kit. A piece of safety wire and a cotton swab will also be included.


This is where to pry the access cover off. You need a similar size screwdriver.


What's under the cover.


You need to pry the retaining clip off.


Work the clip off by prying back and forth from alternate sides.


This is the best place to pry the vacuum lever up. It comes off easily.


Next you wire this out of the way. Not necessary but very helpful.


The best way to pop the bell crank lever out is to pry here. Again you need the proper size screw driver to fit in here. You need to get between the seal boss and the lever, then pry and twist. If you have a used DISA this piece may just fall out or be able to be pulled out by hand. If you are retrofitting a new DISA you will need to pry it out.


Here is the bell crank. This is a new one, a used one may look different depending how much plastic has been worn away.


This is a critical proceedure if your DISA is new or the pin is still fully seated. The pin head is very thin and sits flush with the top of the support bearing, so there isn't an easy way to grab it. You need to get a proper size screwdriver blade that just fits between the top edge of the flapper valve and the underside of the framework at the location shown. Position the blade so when you twist the scewdriver, it will pry up on the framework. Again a used DISA may have the pin already falling out and you can skip this step. If you have one with the pin fully seated, be careful not to damage the framework.


This is what the pin head looks like after prying the framework. You need only pry enough to form a gap under the head.


Now you can remove the pin with a pair of diagonal cutters.


This is how long the steel pin is. It's pressed in pretty tightly on a new unit. This is what has ruined a few engines after it fell out and went through the intake runner and into the cumbustion chamber.


The flapper can now be slid out of the frame work.


Once you have the flapper and bellcrank removed you will want to clean the rest of the DISA. I recommend using a full strength industrial cleaner like Simple Green or Purple Power from Auto Zone. I would avoid brake cleaner of solvents as they make make the plastic more brittle. Note the little hole being pointed to, this is the vacuum port hole that actuates the DISA. Plug this with a tooth pick or something to avoid getting excess water into the chamber. Use a tooth brush (the wife's, if it's her car) and the cleaner and work at it until it's acceptably clean to you.


Once the DISA is clean and dry you are ready to begin reassembly. Apply a nice glob of the supplied grease to the cotton swab.


Apply the grease to the inside lip of the bell crank seal as shown.


Apply a little around the perimeter of the bellcrank shaft.


Note the rotation as shown and install the new lubed up bellcrank.


Sorry some of the pictures are a little out of focus but you can still see what needs to be seen. Push the bell crank all the way in as far as it will go. It should look like this and will probably have grease all over the tapered hex from pushing it through. While keeping the bellcrank pushed in with your finger, completely clean the protruding hex taper with a clean cloth and solvent. Brake cleaner, acetone, etc.


Next, with a clean finger, push the bellcrank back until it's flush with the surface as shown. The goal is to keep it centered in the hole so that you don't get any grease on the taper again. The seal will hold it in place.


Apply some of the supplied threadlock to the end of the cotton swab (preferably the non-greased end) as shown.


Then wipe a thin film inside the female hex pocket of the new flapper valve. Don't over do it, it should just be wet on the sides.


Now you can slide the new valve in place. This is the only orientation that will allow the flapper to slide in due to it's shape. It goes in from the side with the vacuum hole with the flapper positioned as shown. It's designed to be a precision fit so it needs to be straight in order to slide in.


Flapper in place.


If you want you can temporarily replace the steel pin and hold it in with your finger while you push the bellcrank into place. Not necessary, but it helps to keep that end centered while working on the other.


This is the position you want the flapper to be in while pushing the bellcrank into place. 90 degrees to the framework.


Make sure that the bellcrank is aligned like this and the flapper is 90 degrees to the framework, then push the bellcrank into place.


Install the lock washer onto the new pivot screw.


Apply one good size drop of threadlock to the end of the thread.


Anything more than this is unnecessary. Excess theadlock could try to make it's way into the end bearing so don't feel the need to over do it.


You can now install the pivot screw. You may want to look down the end of the support bearing hole to help with aligning the end of the pivot screw with the hole. You will want to hold the flapper in the closed postion while tightening the screw with a 5mm allen wrench or hex driver. You want the screw very tight to fully seat the tapered surfaces together. Once the screw is tight, make sure the flapper rotates freely back and forth.


You can now put the vacuum pot lever back over the bellcrank pin and push the retaining clip back on.


Reinstall the plastic cover and your finished. Double check that the flapper will rotate from the 90 degree postion to the closed position, then when released return to the 90 degree position on it's own.

I don't know if all the detail shown here makes this seem like an involved job? It's actually pretty straight forward and very do-able for anyone with decent mechanical skills and a few basic hand tools. What do you all think?

Oops, I forgot a couple of things. These are the instructions for the replacement seal.


The M54 has the main seal molded into the framework which is why BMW don't offer a replacement O-ring.



The molded in seal needs to be scaped out with small flat blade screwdriver or similar Non-sharp tool that will fit into the groove. After scraping the molded silicone out, you can use a fine-wire stainless steel or brass brush (Harbor Freight) to remove the little remnants. The groove should look like this when you're finished. Be careful not to scratch or gouge the groove. If you are retrofitting a new DISA you can skip this step and keep the new O-ring in stock for a future failure.



Once the groove is cleaned you can install the new O-ring. I squeeze some of the supplied grease onto my fingers, then work the grease onto the surface of the O-ring before installation. This not only helps ease the reinstallation of the DISA into the intake manifold, but also aids in sealing.

Nice - very nice. As a machinist, I can appreciate the work you put into this project. True dedication!

It's times like this that I kick myself for not going into engineering in college or at least learning how to machine things. You do realize that you have the potential to become obscenely wealthy from this if you can mass produce and market correctly? (Think about what Beisan did with those replacement Vanos seals)

Question: Is the diaphragm robust enough to handle the extra mass of the new flapper and pivot? I wonder if this fix will move the failure point of the DISA valve from the flapper to the diaphragm.

Chisum

Very nice work! Too bad all that beautiful machine work remains unseen inside the black plastic box. Great work, thanks for doing this. Hope the M52 is not far behind (hint, hint...)

Originally Posted by ericono

Very nice work! Too bad all that beautiful machine work remains unseen inside the black plastic box. Great work, thanks for doing this. Hope the M52 is not far behind (hint, hint...)

You have a DISA in your M52?

Originally Posted by ericono

Very nice work! Too bad all that beautiful machine work remains unseen inside the black plastic box. Great work, thanks for doing this. Hope the M52 is not far behind (hint, hint...)

How about designing a clear plastic housing so that we can appreciate this engineering beauty?

What's the kit going to cost?

jarhed1964,

I think I do. Isn't that what #6 is in this diagram: http://www.realoem.com/bmw/showparts...95&hg=11&fg=40

Eric

Originally Posted by ericono

jarhed1964,

I think I do. Isn't that what #6 is in this diagram: http://www.realoem.com/bmw/showparts...95&hg=11&fg=40

Eric

Oh, ok. Yours is a 2000. My 97 is a straight M52. No DISA. Pretty sure my 99 has it though.

Excellent work BikeStillRules.

Once the titanium pin is out I'll snag a kit from you.

If you are retrofitting a new DISA you can skip this step and keep the new O-ring in stock for a future failure.


What! More possible failures!!! I thought this was to cure all that. LOL Seriously, I hadn't realized this was for the only for the 530 style of Disa valve. Is the 525 version so different? Aren't they both M54 engines only varied by perhaps stroke or bore size? Cost anyway?

Forgot, great instructions but with the product you created and the detail involved why would anyone be surprise.

Question: Is the diaphragm robust enough to handle the extra mass of the new flapper and pivot? I wonder if this fix will move the failure point of the DISA valve from the flapper to the diaphragm.

Thanks for asking. If I've missed something, I need people to bring it to my attention so I can address and correct it. If someone has a concern that is a non-issue, I need to be able to respond and clarify why I think so.

1) There is really no mass related load put on the vacuum actuator. The system moves slowly enough that the small rotational inertia difference if insignificant.

2) The vacuum actuator is fully loaded the entire time that the valve is in the closed position, which is most of the time. That aspect doesn't change with the aluminum parts compared to the plastic ones. Since the OEM design has the diaphragm under full vacuum load to keep the valve seated against the molded in silicone rubber gasket, and since that load is many, many times greater than the force required to rotate the valve, it's a non-issue.

What's the kit going to cost?

No definite price yet.... but based on known material costs, current machining time, blasting, anodizing, etc. Expect the complete kit to come in at around $85-$89.

I think I do. Isn't that what #6 is in this diagram: http://www.realoem.com/bmw/showparts...95&hg=11&fg=40

Yes, that's it. If you have a used bad one I would be happy to pay your packaging and shipping costs.

Once the titanium pin is out I'll snag a kit from you.

Great! Thanks doru. Just for reference, the new parts only weigh 13.5 grams more than the stock plastic valve with steel pin.

Is the 525 version so different? Aren't they both M54 engines only varied by perhaps stroke or bore size? Cost anyway?

I don't know yet what if any differences there are between the 2.5L & 3.0L DISA units. I just know that they have different OEM part numbers. We are all hoping that the 2 parts that matter are the same. If not I will need to make a different flapper for the 2.5L versions. I can't imagine that the bellcrank lever is any different.

Can't wait to buy one of these master pieces.

It looks great - very impressive.

In the photos, the bell-crank part looks like it is round instead of hex/flat-sided to fit into the flapper. Is that the case? Or is it just the pictures?

In the photos, the bell-crank part looks like it is round instead of hex/flat-sided to fit into the flatter. Is that the case? Or is it just the pictures?

It's a tapered hex with radiused corners but it doesn't show up that well in the pictures.

Good news on the 2.5L version. Someone very nice on this forum says he has an old one and is willing to send it to me so that I can measure it. I didn't mention his name because it was a PM and maybe there is some silly reason why he might not want to take credit for his generosity. I don't like posting something from a PM without permission.

Sorry for the 3 posts in a row but I forgot to ask something. I didn't get any feedback on the instructions and pictures. Do you think it's too much, too little, or just the right amount of detail? Did everything posted seem clear and concise? Is it stupid to include cotton swabs and a short piece of safety wire? My thought process was based on my own laziness. If I'm out in the garage, in the middle of a project, and I read instructions that say to apply something with a cotton swab, I'll grab anything handy to use that might work, instead of going into the house to get a cotton swab. Same idea applies to the threadlock. Many of you probably already have a threadlock compound in your possession, but there are so many different types, and whenever you grab an old bottle it's always plugged up or something. This way everything you need, except a few basic hand tools, is there at the time you open the package.

Just so you know, I didn't respond to your request for feedback because I have the V8, and I didn't really feel qualified to comment on the merits of your instructions. However, as a spectator to this thread, I was impressed that you took the trouble to provide a complete, self-contained kit. As someone who appreciates clear writing, I thought your instructions and photographs (despite being somewhat out of focus) complemented each other well, and I would feel confident following them.

Originally Posted by BikesStillRule

Sorry for the 3 posts in a row but I forgot to ask something. I didn't get any feedback on the instructions and pictures. Do you think it's too much, too little, or just the right amount of detail? Did everything posted seem clear and concise? Is it stupid to include cotton swabs and a short piece of safety wire? My thought process was based on my own laziness. If I'm out in the garage, in the middle of a project, and I read instructions that say to apply something with a cotton swab, I'll grab anything handy to use that might work, instead of going into the house to get a cotton swab. Same idea applies to the threadlock. Many of you probably already have a threadlock compound in your possession, but there are so many different types, and whenever you grab an old bottle it's always plugged up or something. This way everything you need, except a few basic hand tools, is there at the time you open the package.

I think it's very detailed. That's what needed - the DISA is not hard to remove, and there might be people who are not mechanically oriented. With all the details, it's a true and easy DIY.

Thanks bud

I think your instructions are great. The blurriness is a bit irritating on the eyes but nevermind

One final quick question: The retaining clip on the bellcrank pin. Since the pin is now metal and hard, will this clip stay in place well enough? Or will you be machining in some notches or something?

Originally Posted by BikesStillRule

You can now put the vacuum pot lever back over the bellcrank pin and push the retaining clip back on.

Has this ever happened to you? This is the second time in 2 days that I had written a long post while drinking coffee, went to set my cup down to the left of my keyboard, bumped the edge of the "Esc" key with the bottom of the cup and lost everything.

If you had even seen how slowly I type with two fingers you would know how agonizing that is to me. The last post was on a different thread, was really long, and when it happened I just gave up and never posted.

So any way.......

I think your instructions are great. The blurriness is a bit irritating on the eyes but nevermind

Thanks, there will be replacement pics for the blurry ones before releasing the finale version

One final quick question: The retaining clip on the bellcrank pin. Since the pin is now metal and hard, will this clip stay in place well enough? Or will you be machining in some notches or something?

I've tried the same used clip on 2 different DISA's with the aluminum bellcrank and it held tight on both, even after being pried off several times. The natural position of the crank is where it rests in the clipped position. I've tried cycling the unit a bunch of times with no clip and it never tries to move off the end of the pin. In fact, if I pull the lever out toward the end of the pin, when I cycle the unit the crank moves toward its natural rest position. I will hopefully be providing a new clip in the kit to cover Murphy's law.

Update on the 2.5L version. The bad news is after looking at pictures of DISA's for sale on ebay, it is clear that the flapper is shaped differently on each version.

The good news is that Chisum has sent me a 2.5L version that should be in my hands on Thursday. Hopefully the flapper is in good enough shape to get good dimensions off from it. Once I have dimensions I should be able to have both versions ready by the time that the custom titanium hardware comes in.