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Refurbish Your VANOS Solenoid Pack

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    DIY: Refurbish Your VANOS Solenoid Pack

    Let me preface this by saying that what I did is basically a copy of what Beisan does with their refurbished solenoid packs. I based my work heavily on the images and descriptions that they have on their website. I probably wouldn't have attempted this if they hadn't shared as much as they did.

    Also, this thing is way more finicky and fragile than I expected. It's easy to mess up and break something. So I would only suggest doing this if you have experience working with fragile electronics, like to do this sort of stuff, or reeeally want to save $150 by not buying the Beisan product. If you're hesitant, it's probably best to just get the Beisan one. No risk of messing up and you get to support a company that puts out great products.

    With that out of the way, here's how I refurbished my VANOS solenoid pack.

    Step 1: Get the solenoid pack and valve body off of the car.

    Didn't take any pictures, but there's a lot of guides on how to do this. This is probably the best one: http://www.beisansystems.com/procedu..._procedure.htm


    Step 2: Open up the pack.

    Once the solenoid pack is separated from the valve body (four E5 torx bolts), it's time to get the solenoid pack open. The pack is made up of two plastic pieces that are held together with plastic tabs and a LOT of silicone. Unless your solenoid pack is pretty much brand new, don't even bother trying to be gentle with the plastic tabs. They're going to break off anyway, so just go ahead and do it from the start.

    Now, there's a couple options for getting the pack apart. You could take a heat gun to it and gently try to pry it apart. It'll take a while, but should work and might yield neater results than the next option.

    However, Beisan seems to cut it off (as is evident in pictures and in their description of the solenoid refurbishment), so I elected to do that instead. Seeing how brittle the tabs were made me worry that I would snap the lid if I tried to pry it off.

    You want to cut around the perimeter of the lid, along the red line:

    Click image for larger version  Name:	Screen Shot 2021-09-18 at 6.35.11 PM.png Views:	47 Size:	612.3 KB ID:	127417

    Don't need to cut too deep, the wall you're cutting is only about 1-2mm thick. Make sure to cut all the way into the two holes in the lid for the e torx bolts, or else the lid will stay attached. Once you've cut all around it, the lid should fall right off. If it doesn't, you missed a spot.

    Here's my pack after the cut:

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    Step 3: Inspect the solder joints to see if there's any failures. Mine were fine, but some cracking had started around some of the solder joints, mainly the middle front one:

    Click image for larger version  Name:	20210915_205502.jpg Views:	41 Size:	96.0 KB ID:	127419


    Step 4: Get the PCB out.

    The PCB is held in by a few torx (T10?) screws, the solder joints and a few dabs of adhesive on the bottom. First thing to do is to remove all the old solder. I heated up the pads with a soldering iron and used a solder sucker to get all of it out. Fortunately the solder points on the PCB are full vias and not just pads on the top, so it's hard to overheat and damage them with the iron.

    The solenoids are attached to the PCB with some thin wires, so be very careful with those, as you don't want to snap them. I ended up basically pushing some of them through (from top to bottom) with the soldering iron, as it was super hard to get all the solder out.

    Once all the solder has been removed, you can lift up the board. You'll need to pry up on it with a good amount of force because of the adhesive used, but it'll eventually come out.

    Solder removed:

    Click image for larger version  Name:	20210916_214221.jpg Views:	42 Size:	107.1 KB ID:	127420

    PCB removed:

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    Click image for larger version  Name:	20210916_214247.jpg Views:	43 Size:	133.4 KB ID:	127422

    It's a good idea to measure the resistance of all four solenoids before continuing, to make sure that none were damaged during the removal of the board. If any were, there's no sense in doing any of the following steps. All four of my solenoids measured in at 6.8 Ω.


    Step 5: Fill in the space between the connector leads with some sort of adhesive.

    I used JB Weld Plastic Bonder mostly because I wanted to try it out. Any electrically insulating adhesive should work though. Pour it into the cavity and make sure not to get too much on the pins. If you do get some on them, wait for it to dry and scrape it off later.

    Also, be sure that all the pins are still where they should be or else you'll permanently glue them in incorrect positions.

    Click image for larger version  Name:	20210917_173900.jpg Views:	41 Size:	226.1 KB ID:	127423

    Before using the JB Weld stuff, I did a few tests with it. First, I wanted to make sure it wasn't conductive, so I stuck a couple wires into some of it and let it dry:

    Click image for larger version  Name:	20210916_214346.jpg Views:	43 Size:	147.9 KB ID:	127425

    It is indeed non-conductive.

    I also wanted to see how it would react to heat. Fastenal says it can withstand up to 350ºF, so should be fine, but I still tested it out. I pointed a heat gun at it for maybe thirty seconds and then tried to pull one of the wires out. The epoxy became very brittle with the heat from the heat gun and I was able to break it off easily:

    Click image for larger version  Name:	20210917_095312.jpg Views:	41 Size:	153.8 KB ID:	127424

    However, if I let it cool back down, it seemed to regain its strength, which is great. Even if the temperature in the pack were to somehow exceed 350ºF, the epoxy will be fine once it cools back down.


    Step 6: Add an extra screw to hold down the board.

    Beisan replaces one of the plastic alignment studs with a screw. They say this helps bring the board "closer to the connector pins". I don't know if this actually makes a difference, but Beisan does it, so I did it too.

    I bought some 4 x 3/8 pan head sheet metal screws to use for this. If you can find something slightly smaller, I'd recommend buying that, but this was the smallest screw I could find at my local hardware store.

    I drilled out the PCB slightly to an 1/8" diameter hole and then removed the alignment stud in the casing:

    Click image for larger version  Name:	20210917_173900a.jpg Views:	42 Size:	226.1 KB ID:	127426

    (yes that's the same pic as before, but it was the only one I had where you can see the stud is missing.)

    Now it's time to drill the pilot hole for the screw where the stud used to be. Be very careful when doing this as one of the solenoids is directly beneath that point. There's ~5mm of plastic, then a bit of white silicone and then the solenoid. If you reach the white silicone when you're drilling, stop immediately. The solenoid starts ~10mm below the plastic surface, so there's a little bit of wiggle room, but it's best to not risk it.

    I drilled a 1/16" pilot hole for the screws I bought and I cut the threaded portion of the screw down to ~6mm (just to be extra sure I didn't hit a solenoid):

    Click image for larger version  Name:	20210917_180240.jpg Views:	41 Size:	202.8 KB ID:	127427


    Step 7: Clearance the lid.

    Since I cut the lid off, I lost a couple mm of clearance between the lid and PCB, so I needed to make some more space. There are three main things on the lid that interfered.

    First up is what looks like a vent with a water barrier.

    I started off by cutting it down with a dremel and a cutoff wheel:

    Click image for larger version  Name:	20210915_211242.jpg Views:	41 Size:	185.4 KB ID:	127428

    Once I got to that point, I was able to pop the center section off. I removed it and kept grinding it down until I had made enough clearance to clear the PCB. After that, I sanded down the center section so that it was flush with the edges. I also used a dremel to remove the two plastic standoff in the lid (middle and right in the picture below):

    Click image for larger version  Name:	20210917_194523.jpg Views:	42 Size:	158.3 KB ID:	127429

    I added a small dab of the JB PlasticWeld to the center section just so that it would stay in place:

    Click image for larger version  Name:	20210917_195134.jpg Views:	41 Size:	51.2 KB ID:	127430

    I then inserted it back in and held it in place with vice grips while it dried:

    Click image for larger version  Name:	20210917_210533.jpg Views:	42 Size:	111.8 KB ID:	127431


    Step 8: PCB reassembly.

    Here's everything laid out after the surfaces were cleaned up and ready to be reassembled:

    Click image for larger version  Name:	20210917_184412.jpg Views:	41 Size:	146.9 KB ID:	127432

    The PCB needs to go on first. Make sure to straighten the solenoid wires and have them all where they should go. The wires are actually folded on themselves, so be sure that they're not shorting out against anything.

    You can see how they're longer strands that are folded over in this pic:

    Click image for larger version  Name:	20210917_184518.jpg Views:	41 Size:	116.6 KB ID:	127433

    Put the PCB back on and screw everything in place BEFORE doing any soldering. Once all the screws are torqued down, add solder to all the pins.

    It's a good idea to recheck that there are no shorts and that the solenoids still measure in at 6.8 Ω.

    Click image for larger version  Name:	20210917_191427.jpg Views:	40 Size:	112.2 KB ID:	127434

    Step 9: Glue the case shut.

    I started off by filling in the slots that used to have the black silicone in them before:

    Click image for larger version  Name:	20210917_214200.jpg Views:	41 Size:	107.9 KB ID:	127435

    I then waited for that to tack up and then ran a second coat of epoxy over that. The lid went on on top of the second coat.

    Once all that was dry, I went around once again with some more epoxy, just to make sure the seal was water tight.

    Unfortunately no pics of this, as I had to work pretty fast to avoid having the adhesive dry on me, but here's a pic of the final product:

    Click image for larger version  Name:	20210918_005220.jpg Views:	42 Size:	82.2 KB ID:	127436

    Step 10: Let everything dry, put it back on the car and go for a test drive.
    Last edited by heinzboehmer; 09-19-2021, 01:22 PM.
    2002 Topasblau M3 - Coupe - 6MT - Karbonius CSL Airbox - MSS54HP Conversion - Kassel MAP - SSV1 - HJS - PCS Tune - Beisan - MK60 Swap - ZCP Rack - Nogaros - AutoSolutions - 996 Brembos - Slon - CMP - VinceBar - Koni - Eibach - BlueBus - Journal

    2012 Alpinweiss 128i - Coupe - 6AT - Slicktop - Manual Seats - Daily - Journal

    #2
    Very nice, thanks for this information!
    2004 Silbergrau Metallic 6MT
    Karbonius/OEM Snorkel/Flap/HTE Tuned
    Ssv1/Catted Sec. 1/SS 2.5" Sec. 2/SCZA

    OE CSL Bootlid/AS SSK/BC Coils/4.10 Gears/ Sportline 8S Wheels/Cobra Nogaros
    RACP Plates/Vincebar/CMP/Turner RTAB/Beisan

    2006 M6 Black Saphire SMG
    Instagram

    Comment


      #3
      That is very interesting.

      I would personally just buy the Beisan unit and support his business. He has done some good stuff for this community, helping address common issues without gouging people.

      Comment


        #4
        Originally posted by cobra View Post
        That is very interesting.

        I would personally just buy the Beisan unit and support his business. He has done some good stuff for this community, helping address common issues without gouging people.
        Yup. If I were doing this on another S54, I'd just buy the Beisan part.

        Way too much a work and you get to support Beisan by buying it
        Last edited by heinzboehmer; 09-18-2021, 11:37 PM.
        2002 Topasblau M3 - Coupe - 6MT - Karbonius CSL Airbox - MSS54HP Conversion - Kassel MAP - SSV1 - HJS - PCS Tune - Beisan - MK60 Swap - ZCP Rack - Nogaros - AutoSolutions - 996 Brembos - Slon - CMP - VinceBar - Koni - Eibach - BlueBus - Journal

        2012 Alpinweiss 128i - Coupe - 6AT - Slicktop - Manual Seats - Daily - Journal

        Comment


          #5
          Wow, a lot of work. I have few comments:

          1. The circuit board assembly was a well design and assembled. In addition to be held down by 3 screws, the board is damped from vibration with 3 strips of silicone between the board and the solenoid module. These glue strips are not for holding the board but to damp out the vibration. It is a very simple 2-layer board with 4 Schottky diodes to protect the solenoids driver chips from back-emf high voltage induced by the turning off solenoid.

          2. Instead of adding that 4th screw on the board, I would just add a dab of thick silicone between the board and the lid to damp that section.

          3. I would not unsolder and remove the board, for no reason.

          4. I guess the weak solder joints are the ones at the harness connector where the vibrating connector can cause the cracked solders. I don't think the tiny flexible solenoid copper wires can lead to cracked solder. The connector removal/installation is the main force that flexed the pins and cracked solder. I think resolder all the pins (connector and solenoids), then add a few strips of silicone between board and the lid is all one should do if this makes you feel better.
          Last edited by sapote; 09-18-2021, 11:42 PM.

          Comment


            #6
            Originally posted by sapote View Post
            Wow, a lot of work. I have few comments:

            1. The circuit board assembly was a well design and assembled. In addition to be held down by 3 screws, the board is damped from vibration with 3 strips of silicone between the board and the solenoid module. These glue strips are not for holding the board but to damp out the vibration. It is a very simple 2-layer board with 4 Schottky diodes to protect the solenoids driver chips from back-emf high voltage induced by the turning off solenoid.

            2. Instead of adding that 4th screw on the board, I would just add a dab of thick silicone between the board and the lid to damp that section.

            3. I would not unsolder and remove the board, for no reason.

            4. I guess the weak solder joints are the ones at the harness connector where the vibrating connector can cause the cracked solders. I don't think the tiny flexible solenoid copper wires can lead to cracked solder. The connector removal/installation is the main force that flexed the pins and cracked solder. I think resolder all the pins (connector and solenoids), then add a few strips of silicone between board and the lid is all one should do if this makes you feel better.
            I do a lot of solder work (custom high-end audio). The solder joints on the connector pins look pretty suspect to me (a good solder joint should be concave not convex/blob of solder like these). I would tend to agree that simply redoing the solder joints would be enough to solve the issue -particularly given the circuit board is apparently thru-hole plated.

            BTW Nice writeup!
            Last edited by poss; 09-21-2021, 02:15 AM.

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