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E36 M3 S50B30 Vanos Rebuild PT3

Right, back with some more Vanos fun!

Part 122.52.6

So, the other day, stuck bolt came out. This finally meant I could remove the vanos unit and begin the rebuild.


First step was to clean up as I left a lot of my destructive tools lying around.

Next up was to begin the removal. First you need to remove all the bolts from the front of the vanos unit (two already destroyed and removed), 6 short, 1 long for 7 in total (not the 9 Beisan says).

Once this is done, remove the 4 bolts across the vanos bridge, and remove the bridge. Note, all 4 bolts are the same length (not 2 short 2 long like Beisan says)

Proceed to carefully slide vanos unit forward a little. Beware of the oil pump driver which is a disk that goes between the vanos unit and the exhaust cam. If dropped, this will take a swift trip to the bottom of the oil pan. Beisan has no picture to show what you are looking for with the driver, so I took a few.

The driver is a disk that sits here.

When removing the vanos unit, my piston got stuck to the shaft that sticks out of the intake cam. I had to use my tack lifter to gently lever it off the helical gear. There is a wee notch in the top of the gear above where the piston is stuck that I found to give just enough room to lever from.


Minor marking from bolt removal

Remove piston (push out with finger)

Pull the intake cylinder apart

Bag of seals

Once removed, ALL parts get a thorough cleaning in a mixture of brake clean and degreaser. The vanos bridge and bolts came up mint.

This is another part Beisan wasn’t clear about. When you replace the seal on the cylinder and you are refitting to the bore, DO NOT PUSH THE CYLINDER IN. Let is rest, and then use the cover to push it in with the tightening of the screws. If you push the cylinder in you WILL ruin the seal like I did >_<

Rest it like this

Put on cover (aligning the indent in the side with the vanos filter next to it). Make sure you remove the o-ring on the cover as per instructions, first. Slowly wind the screws in, bit by bit and doing them in a star pattern until the cover is seated completely. It’ll come out like this.

Don’t forget to renew the seals on the piston. They’re bit of a pain to do.

Clean the cylinder cover and renew the seals on that too

That’s that side done. Next up is to remove the oil pump cover. My bolts were really tight, so I soaked in CRC (penetrating oil), cracked then, wound out 3 turns and then put more oil on them and left to soak.

Pause for break.

The CRC worked a treat, all the bolts in the oil pump cover came out OK. The cover itself was a real shit to get off but some persistence and brute force popped it off.

Insides were a bit black but no chunks or sludge. Gave it a wipe down and replaced the seals.

Yeah Boi, I own a Rolls.

Vanos unit all back together

Next up was the solenoids. I had done a lot of research on how best to approach this, and the E39 M5 boys have some pretty good info about it (same solenoids).  I decided it was best to replace the seals, remove the gauze ring and clean the solenoids. The gauze ring is the brown bit you can see in some of the photos of the solenoids. It’s a plastic ring with some gauze filled slots.

My gauze rings were fooked. The gauze was missing in places, and the rest was blocked. Used a scalpel to lever it off slightly, and then some pliers to break them and pull them off.

I then turned my attention to the cleaning of the innards. Obviously I can’t disassemble them, so had to find another way. The best way people tend to use is to flush them with brake clean whilst actuating them. I went with this method.

Out came the 9V battery and connector.

The solenoid leads are moulded with the polarity on the connector, so just join + to + and – to – and hopefully you should hear the solenoid click. I didn’t.

It turns out the top solenoid was dead. Nothing at all. I began to flush it by blasting brake clean into the ports, and after a few tries I finally get a faint click from it. Yay! I spray and actuate a few more dozen times until I’m getting a nice, solid, hearty click every time and then move on to the next one.

The lower solenoid wasn’t as bad, it clicked first try but was very faint. A thorough cleaning fixed that, although some of the shit that came out was pretty nasty.

Replaced the seals on both, and put them aside.

Replaced the vanos filter. Old one was black and you can see blockage in the gauze. Its cheap and easy to get at so I’ll replace this again in a thousand km or so.

To be continued.

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