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VANOS Solenoid Maintenance_Full DIY

138K views 255 replies 63 participants last post by  JohnAnthony 
#1 ·
Hey everybody. I just did the VANOS solenoid O-ring replacement and solenoid clean / soldering two weeks ago. All the information is already on the board but I thought I would condense it into one simplified thread. Thank you to all members who contributed information that lead to the creation of this DIY. If you have anything major you think should be added (only the most necessary of things) let me know and I will add it.

PARTS LIST
11-36-7-830-828 x 8
11-36-7-830-829 x 8
11-36-1-406-838 x 2
12 V power source (8 D batteries in series with some breadboard wire works the best)
Compressed Air Can
6mm Allen Socket and Torque Wrench
Brake Cleaner
MAF Cleaner (or some other electrical contact cleaner)

Torque Specs:
Solenoid Screws - 16NM
Cover Bolts - 19NM

Time Allotted: Minimum 6 hours. I gave myself an entire evening to do this. I suggest you take your time, as these are expensive!
WHY TO REPAIR? Especially on older models, these O-rings will give out. Notice any oil leaks around the VANOS? VANOS timing seems off, engine sluggish?



FIRST STEPS
1) Depressurize the coolant system by unscrewing the radiator overflow tank cap, wearing gloves of course! Remove airboxes and Intake hoses.
2) Using the 6mm Allen socket, back (halfway out) the 4 solenoid pre-tension set screws. IMPORTANT to do this first. You can get to all of the bolts by bending the radiator hose out of the way while you are wrenching.
3) Slightly loosen the 5 VANOS cover bolts with the 6mm allen, starting in the center and then working your way around the outside.
4) Remove all 5 VANOS cover bolts.
5) Place a rag underneath the VANOS to catch any residual oil drip from reaching the belts.
6) Remove the VANOS cover being careful with the wiring harness that attaches to the board.





7) Spray out the cover with brake cleaner, removing all oil residue.
8) Unplug the wiring harness from the clip and make sure it will easily come out when you pull the boards.

SECOND STEPS
1) To pull the solenoids I used a wrench with as much 90 degree bend as I could find. It had teeth, which I covered with a layer of masking tape to avoid any major scratching.
2) Pull firmly and consistently while twisting about 20-30 degrees to loosen the solenoids. You will feel them pop when the o-rings slip. PLEASE WATCH THE VIDEO posted by Vantaam5
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/144368-how-remove-solenoids-video.html
3) Once all 4 solenoids have been been loosened from their force fit, carefully pull the board and wiring harness from the housing.
4) Spray out the housing with brake cleaner, covering all rubber belts with a towel.

THIRD STEPS
1) Gently remove the VANOS board and harness. The only thing holding it in were the interference fits from the solenoid o-rings. Be careful not to twist the VANOS wiring that connects the board to the solenoids.
2) Place the VANOS on a flat work surface with ample room and spray lightly with electronics or MAF cleaner to remove oil.
3) Start to remove o-rings. If the o-rings still have some life left in them they will be tough to get off. I found it best to gently cut them with a hobby knife and pull with needle nose pliers till they ripped.

FOUND MY LEAK SUSPECT!


4) Remove the gauze filter holders. Plastic rings with ovular windows. Remove all residual gauze filter and spray the area with MAF cleaner.
The easiest way to remove them was to press a hobby knife in the underside of the ring and leverage it upwards. Most of the time they cracked and then were easy to pull off.



5) Now you want to actuate the valves and spray the inside with compressed air to expunge residual oil. In order to do this, and i found to be the easiest way, I went to radioshack and purchased 8 D batteries (8 x 1.5V=12V) and wired them in series with qty 2, 4 D battery holders. I then twisted the two grounds and two leads from the holders together. I bought a pack of breadboard circuit wire and tied one wire each to the ground and lead (power) wire.



6) Examine the wiring schematic attached to the end of this post by member gzig5. DOn't over think it, it's simple. Each solenoid has it's own lead (power) and two solenoids share a common ground. Press the ground (black) wire on either of the middle contacts (black arrow) and then actuate the two solenoids by attaching the power (red) lead to the contacts above and below it, seperate times of course. Spray inside the tiny valve once each is actuated. It makes a high pitched click sound.



7) If all solenoids actuated then the contacts are fine, but you should re-solder the connection between the board and solenoid anyway. If one doesnt actuate examine the tiny breadboard (suspended) that connects the VANOS board wires to the solenoid wires. Make sure the gaps are soldered well. If they are not, I recommend placing a small piece of wire (no insulation) in the gap and soldering over it.



FOURTH STEPS
1) Here comes the easy stuff.
2) Dip the o-rings in engine oil and replace the 8 that go one each board.
3) Carefully insert the board back in place by evenly inserting the solenoids into their slots in the housing. DO NOT PRESS IN YET.
4) Back out the solenoid pretension screws from the VANOS cover and spray the threads and cover holes with brake cleaner. Let dry and insert the screws halfway back in.
5) Make sure the harness is in the right orientation and the electrical connector is placed in the right area to be easily connected.
6) To press the VANOS solenoid board into place takes some force...As it should for a tight fit. To do this I recommend taking the VANOS solenoid cover and turning it backwards. Place the cover against the solenoids and press firmly and evenly on the cover to distribute the force across the solenoids. They should start to slide in and then pop into place.
7) Now place the replacement paper gasket on the face of the VANOS board housing.
8) Place the cover back in place, making sure that the rubber covering / gasket for the wiring harness is in the correct orientation on the with the VANOS cover.
9) Place all 5 solenoid screws in place and hand tighten as much as possible doing it evenly around the cover.
10) Bolt down the 5 cover screws per the torque spec listed above.
11) Torque down the pretension screws per the torque spec above. Make SURE to tighten them as straight as possible or they WILL jam in the threads.

FIFTH STEP
1) Double check your work and make sure everything looks good and no missing parts laying around.
2) Start the engine. Don't be alarmed by initial rattle as it is the system re-pressurizing.
3) This should be it. Monitor the VANOS for the next few days to check for oil seepage.

I hope this helps out members looking for a one stop shop to doing this job. I had like 4 threads open when doing this. If you have any suggestions to add (that are NECESSARY only) please let me know and I will try and add them.

BEST OF LUCK!
 

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#2 ·
When removing the solenoids, it can be very hard to get them out. You should wiggle each one, and try to release a mm at a time. Dont pull one all lets ge way out then go to the next. When rotating them iniitially, make sure you FIRST roatte in a way that loosens the wires.

Using a vise grips to hold each, then with a large screwdriver, etc you can pry them up. This is more controlled then your muscles pulling (Which if it lets go can damage the board)

Once you collect up edits and comments, I can clean up the thread too.

Thx

A
 
#4 ·
I was looking for a detailed step by step like this nice work!
 
#6 ·
O ring size...please help

Ji Guy's

Does anyone give me the exact size of the O ring's on the solenoid?
I can buy viton here in my country, just in the shop they dont know the size what I nead. On the net a lot of talking about how good the new O rings...just no any valuable info abouth the size. (internal and outher diameter and how thin in mm).


Thanx

Frank
 
#8 ·
Ji Guy's

Does anyone give me the exact size of the O ring's on the solenoid?
I can buy viton here in my country, just in the shop they dont know the size what I nead. On the net a lot of talking about how good the new O rings...just no any valuable info abouth the size. (internal and outher diameter and how thin in mm).


Thanx

Frank
Frank,

The o-rings, at least the large ones, are not circular in cross section so I don't know if standard o-rings will work for that one.
Greg
 
#9 ·
#13 ·
Thanx the info.

The smaller O ring "D" shape to?
If I look the cross selection image...I dont know how "high" the "D" . Probably the diameter is a bit bigger than the hole in the head for solenoid. In the shop they have every size (viton). The prise is allmost nothing. The oem BMW's O ring set prise more than 10-15 times higher.
 
#14 ·
Since it is pretty easy to change these o-rings, I think it is worthwhile trying standard round cross section o-rings. After all, they work well for the rest of the world. The only problem might be if BMW made the o-ring grooves in the solenoid valves an usual size to accommodate them.

Yes, the smaller o-ring was d-shaped too. Come to think of it, I used the Dr. VANOS set, so I don't know for sure if the OEM o-rings are d-shaped.

To get the size of o-rings you need, you need to take some accurate measurements and use design guide 4.2 in this catalogue.

http://www.parker.com/literature/ORD 5700 Parker_O-Ring_Handbook.pdf

This standard seems to be used world-wide even though it uses imperial, not metric, sizes.

For up to 1500 psi, design guide 4.2 recommends 22 to 32% squeeze on the o-ring cross section when installed. Since this is a static seal (it doesn't have to slide in bore), the squeeze is not that critical. You should probably keep it to the low end if you can, to avoid the risk of cutting an o-ring or having to apply to much pressure when installing the board.

I don't know if you can get o-rings of various Shore hardness but stay in the 70-80 range. The Shore hardness number is usually at the end of the part number.

Viton is a very good material for oil and heat.
 
#15 ·
I have a theory....

The O ring can keep so long, if it is "O" or "D" shape. The problem is the cover of the older version aluminium plate. This plate keep the 4 solenoid in place. I think beeetween the top of the solenoid and the aluminium cover have a gap. this gap alow to "shake" the complette solenoid in and out a bit. That's why the wire and the soldering point not last so long, and the O ring wear.
I saw on the net the newer version of the solenoid cover have 4 screw to keep tight position in the hole. Maybe after some years not bad to check the tight of this 4 screw.
Whitout this "fixing" screw all of the solenoid shaking in and out a bit in the hole. This moving kill the O ring.
 
#18 ·
The older covers without the 4 clamping screws definitely made life harder for the o-rings. There was a thread not long ago with some photos of the solenoid valves on an early car and the o-rings were in a terrible state, badly worn due to the valves moving.

I don't think the 4 screws on the later covers can come loose. They are secured with a thread sealant that keeps them tight.

If you have an earlier cover, you can modify it by adding the clamping screws.
 
#16 ·
Overall very good thread. Great consolidation of the process and procedures.

A few comments:

1. After using the Dr. Vanos O-rings, I would probably due the job with OEM given the ease of getting to these solenoids and the cost delta?

2. I would not bother with backing the stub screws out as long as you do not mix up the boards and covers. The hex stub/scrub screws have some sort of thread locker and are not easy to move.

3. I would just use a 9 Volt battery and some small alligator clips, probably cheaper and easier to get your hands on.

4. Prefer a full air compressor with a rubber tipped blow gun to really seal up on the center of the solenoid and really blow any trash out of the solenoids. Canned air will probably work, buy I wanted to make sure there was no trash inside the solenoid.
 
#17 ·
If I'm honest, having most of the threads on these O-rings, I'm likely to go for standards. I think I remember they were redesigned at some point before now anyway. If they only last x0,000 miles, heck, I'll replace them again. It really doesn't seem the biggest job.

Is it really worth trying to find alternatives, given that these are O-rings, how much can you save on these parts?
 
#19 · (Edited)
Anyone have any good advice re the soldering? I read in another thread (sorry I lost the link and just copy/pasted the info for my own awhile back) about using high-temps solder:

"I took the solenoids apart and resoldered the joints due to the fact people on enthusiast forums claim cold solder joints can develop over time. I kind of wish I didn’t do it, though, because I reflowed the boards using regular consumer electronics rosin core solder. This solder is not designed for the heat found in automotive applications, but will work for now. At a later date, I am going to remove the solder and use a higher temp solder with good nickel content to assure reliability."
 
#20 ·
I call BS on the comments. I have been doing electrical/electronic work for before the E39 was even built. The harder the solder, the higher the melting point, the more brittle it is and the more likely it is to crack with vibration and thermal extremes. There are some applications that silver solder and/or higher temp alloy works better for, these are usually for connections that need a better, more durable physical connection along with an electrical connection. The lead free solder is more a health/environmental issue, but by default due to the alloys used, it has a higher melting point and is more brittle.

Just look at all the Xbox360/Playstation 3 ball grid array solder joint failures!! You do not even want to how many of these systems I have repaired.

The solder on these current boards does not appear to be lead free or higher temp alloy from the ones I have worked on.

I think the earlier VANOS solenoid boards without the grub screws are more likely to dance around and have problems, but I have re-soldered many of these board without problems.
 
#21 · (Edited)
So jfoj, for the average only soldered once or twice here and there person, what kind of solder exactly would you recommend be purchased for this job? :) And if someone isn't entirely experienced at soldering do you think that they are better off not trying to solder the joints together as long as they are not cracked/separated?
 
#22 ·
It seems to me that the whole "gotta resolder your VANOS solenoid board" concept seems to have become some sort of requirement...

... but it seems to me more prudent to replace the orings (as these ALL age) and only resolder if there is a solder failure (confirmed by an open or solenoid control failure)...no?
 
#23 ·
I use a 60/40 lead/tin rosin solder like this - Amazon.com: 7 60/40 Solder Dispenser Tube: Electronics

An a 40-60 Watt Soldering pencil like this - Amazon.com: Sinometer 60 Watts Soldering Iron, UL listed: Home Improvement

I bridge the small circuit boards on the solenoids themselves, meaning I create a solder bridge from the wire to the solenoid connection, about 3/16"-1/4" in length.

Then I retouch all the wire connections on the circuit board as well.

The diodes or components I carefully inspect them, but usually the workmanship of these devices are fine, however, sometimes people bump these devices when removing the solenoids, so I usually make sure they are all in good shape after all the wires and the small solder bridge is make on the small boards on the solenoid.

Luckily this is not ultra precision work, so as long as you get the joint hot enough to reflow the solder and add a bit more, most novices should be able to do a decent job.

The secret is to warm the joint and then add the solder, do not try to melt and drip solder on the joint. Always "tin" or melt fresh solder on the tip before each soldering attempt. The with a quick flip of the wrist let the excess solder fly of the tip of the iron onto some old cardboard. It will cool very quickly. Suggest you wear eye protection if you are new to flicking solder off the iron. I have been doing this since I was 10 years old. Lets just say I have close to 40 years on and off doing solder work, component level repair and surface mount assembly so I have a bit of experience doing this. But you have to start somewhere.
 
#26 · (Edited)
I have been doing this since I was 10 years old. Lets just say I have close to 40 years on and off doing solder work, component level repair and surface mount assembly so I have a bit of experience doing this. But you have to start somewhere.
OK, so how old were you when you built you first Heathkit? What was it?

:haha:

PS Nobody is answering my query of 'why all the resoldering'?? Again this seems to have morphed from a repair that a few have neeed to do to address specific faults, to a 'just do it for PMs sake'... why?
 
#24 · (Edited)
I agree with jfoj, these repairs do not require some super technical NASA level soldering skills. If you have even limited experience with a soldering iron, and limited electrical knowledge (e.g. you can wire up a trailer lights or a car stereo), you will be fine. Once you get the board out and look at it, you realize that it is not that complicated.

I have done two different repairs on my early (no set screw) VANOS boards, and have the following comments:

1. I used a cheap iron and solder, probably picked it up at Walmart or Autozone several years ago. My first VANOS repair was over a year ago and the solder has not failed yet under daily driver use. I wouldn't get too bogged down in the details of "what solder to use" or "what temp iron to use".

2. I accidentally fried one of the diodes when doing a repair. You can get a 10 pack of diodes at Radio Shack to use as replacements. I think I paid about $2.50 for the pack.


3. Wiggle the wires and solenoids when testing, especially if your doing a repair because your car is throwing VANOS codes (for US driver's side that would be 4A, 4B, etc...). I chased an intermittent short that I thought I fixed twice, until I finally found it by moving things around while testing.

4. I'm not sure I would go in and start re-flowing every joint just as preventative maintenance when changing the o-rings, but if your car is throwing codes, it's not that hard to repair/resolder/rewire these boards, and save yourself $1000+ per board.
 
#25 ·
I'm adding this task up to the list of DIY I want to do this year. Thanks for posting this!
 
#27 ·
My first Heath Kit was probably 11-12, I actually lucked out and ended up getting a few that adults put together wrong and they did not work and I was able to make the corrections!! What was fun was the Super TV HBO receivers that used a coffee can and a Yagi antenna with PCV pipe, threaded rod and washers. I was watching free HBO when there was no cable available!!

So here is the deal on soldering, spend the $10 on Rosin core 60/40 solder, get a least a 50 Watt pencil iron, DO NOT USE AN UNGAR TYPE OF SOLDERING GUN!!, then get some lamp cord or some type of speaker wire, strip the insulation, twist the wires together and start to practice. The key is to heat the wire and touch the solder to the wire/soldering tip interface and make sure the solder "flows".

The main area to focus on are the very small cirvuit boards that mount on the solenoids. You want to create a solder bridge between the wire and the solenoid terminal and bypass the small circuit trace. While you are at it, I typically reflow all the connections, maybe not necessary, but as I recall this comes out to about 15 connections on the larger VANOS board and 8 smaller connections on the solenoids, about 10 minutes per board, maybe 15 if you are new to this.

I fix broken and cold solder joints and bad capacitors in everything from gas water heater controllers, flat screen TV's to game systems. Probably repair easily at least 1 thing a month with bad/cold solder joints.

Any yes I have replaced the door lock relays in the GM5 modules for the E46. They take SKILL and even challenge me due to the lead free solder with the high melting point and the dual layer circuit boards along with the silicon sealer potting compound all over the circuit board!

I have yet to have to repair an ABS controller, I am just waiting for one of these to show up on my door step.

Broken circuit board traces and bad solder joints are all over the place. It amazes me how easy these are to repair and how many are out there!
 
#32 ·
I could really do with some advise on this, would be VERY grateful. I have replaced the seals on the vanos solenoids, as you look at the car from the front the right hand side has gone back together perfectly. However, the left hand side, ive put it all back together, to the correct torque settings, started the engine and it makes a clackity clackity sound. I immediately switch off the engine, and take off the left solenoid housing and the solenoid has been pushed out, only two of the four solenoids still holding on. I dissemble the whole thing and put it back together again, ensuring each solenoid clicks into place, start the engine, and again clackity sound is back. I have not dissembled it again but i assume its done the same thing again!

Has anyone any ideas please?
 
#33 ·
VANOS noise is expected until you can get a fair amount of oil circulated in the VANOS system as I recall.

Would expect maybe 30-60 seconds and the noise should diminish and probably be back to normal within a few minutes. You may need to bring the engine slowly up to 3k rpm and then back down to idle a few times to make sure the solenoids activate a few times to circulate oil.

As for the solenoid covers with the grub screws in them, as long as you plan on putting the same solenoids back in the same location and keep the solenoid covers on the same head, you really do not need to even loosen the grub screws. Just treat the solenoids and covers as if they do not have the grub screws in them.
 
#39 ·
Thank you, good idea. But, how do the pre-99 cars hold in at all if they have no grub screws?

Or has the cover been assembled in the wrong position in relation to the board ?
Thanks Clayton, what should the position of the wiring loom be at? I have it at 4'o'clock position so to speak and the housing on to suit, as obviously the recess in the housing has to go over the loom. The right hand side I have set at 7'o'clock position, I mimicked the right hand side, maybe this is incorrect?
 
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