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Discussion Starter · #1 · (Edited)
A few forwords:

This is a DIY for people who have a basic understanding of how engines work.I would not recommend to attempt this procedure if you do not know what you are doing.
Setting the timing wrong might end up in bent valves.
As usual,if you follow this DIY and destroy your engine,I am not liable in any way.


Remove the air filter boxes,intake tubes and plenum.
Remove the ignition coils,spark plugs(put some paper in the spark bores to prevent bolts or other stuff entering the combustion chamber) and the plenum.Also it makes life easier to turn the engine by hand,if you remove the fan.

Remove the oil galleries on top of the cam(10mm socket,10NM tightening torque),do not mix up bank1 and 2 as they are different.

Rotate the crank shaft clockwise until you can lock it on the vibration damper in ignition TDC cylinder 1(look at the intake and exhaust cam on cylinder 1,both valves are shut).Lock the crank,BMW uses a special tool for that.I use a 8.5mm drill,which fits the hole on the vibration damper.The hole in the bracket on the block is larger than 8.5mm.To compensate for this,I wrap electrical tape around the drill until it is a tight fit.



For the next step,BMW uses the toggle switch tool to move the Vanos in initial position.
Notice the position of the Vanos gear to the sprocket gear on inlet and exhaust cam,this is initial position..



Instead of using the switch tool,I remove the solenoids,as this also releases the pressure in the system and makes it easier to rotate each cam against the direction the engine turns it to full stop.For this a 27mm open end spanner is needed(in some cases it is needed to modify the outer edges of the spanner that it is possible to turn the cams without damaging the cylinder head).



If the cam stops and is not fully rotated to stop,turn it back and forth until it is.


To make it easier seeing if the Vanos pistons are in full initial position,it helps to remove the covers of the pistons(each cover 3 bolts,5mm inhex,tightening torque 10NM).
In the pic below you see on the lower Vanos unit the position the pistons have to reach.



The markings on the cams and covers should match now.Notice in the pic below the groove in the cam is smaller than the gap in the cap.If it is within,everything is fine,if not the cam timing needs adjusting.



Rotate the crank clockwise 360 deg further to overlap TDC cylinder 1.Lock crank.Slacken the accessible 3 sprocket bolts per cam 1/4 turn(10mm open end spanner,tightening torque 10NM).

Remove locking tool,turn the crank clockwise 360 deg to TDC igntion cylinder 1.Lock the cams with an M8 bolt or 8mm drill per cam.

If the holes do not line up,use the 27mm spanner to rotate the cams until you can insert the locking bolts in the cams.



Slacken the now accessible 3 bolts per cam 1/4 turn.

Tighten the 3 accessible bolts per cam again with 10NM.
Remove all locks on cams and crank,rotate crank 360 deg to TDC cylinder 1 overlap and tighten the rest of the bolts again with 10NM.
Rotate the engine clockwise 360 deg to TDC ignition cylinder 1.Now rotate the crank clockwise 2 full turns,means 720 deg.
Insert the locking tool in the crank at TDC ignition cylinder 1.

Repeat the adjusting process on individual cams if needed.

After the timing is correct,I suggest using blue Loctite medium on the hex bolts of the sprocket.
I have seen those back out,even when tightened with the correct torque.

To do so,remove one bolt at a time.you get them in the right position almost completely out.Use brake cleaner and compressed air to clean bolts and threads.Apply Loctite on the bolts and tighten them with 10NM.
Is a bit of a pain,as it is 24 bolts,but these can cause serious destruction.
On a side note,BMW delivers new bolts in 10.9 strength,the original ones are 8.8 strength.
To change the bolts,Vanos units and upper chain covers have to be removed.
I will write about that in another thread.


Use new Valve cover gaskets,apply liquid silicone sealant where cylinder head meets upper chain cover and on the rear of the cylinder head.Also replace the rubber grommets for the valve cover bolts.
Assemble the rest.

When starting up,the car will have nasty Vanos rattle for max 30 seconds,because the Vanos is empty.

Get yourself a beer....
 

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Great write-up Raikku, thank you! I've been looking forward to this DIY.

Regarding your statement:

"For the next step, BMW uses the toggle switch tool to move the Vanos in initial position."

Does your procedure require use of this tool, or does it bypass the requirement for it's use by your manually
rotating the camshafts and then locking them in position with the pin (drill bit shank)?

Regards,
Alan
 

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Rarrrrrrr!!!!!!

Been waiting for this for ages.

Nice one

Just a quickie .

Are you removing both the solenoids as per your other DIY AND the piston covers? The pic you showed only shows the piston covers off but if i'm correct you are using that pic for illustration?

Secondly, if your cam timing marks don't line up, i take it the 6 bolts per cam if you like, are on slots enabling you to just essentially loosen them and move the cam slightly whilst the chain holds all the timing still together??

Also lastly i take it as you rotate the cam backwards (bolts still tight initially) that you are in effect moving the vanos by hand to its most retar-ded "initial" position?

Sorry to ask whats probably obvious i just want to clarify mate

Cheers dude.
 

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Discussion Starter · #8 ·
Correct,Jamie.
I only used the pic for illustration.Is actually pics of 3 or 4 different cars even..LOl

Solenoids have to be removed.

You are right,The sprockets have slots where the bolts move in.
 

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great write up man! :) theres an easier way which dosen't require the use of the vanos tools or removing the solenoids to remove the vanos units. just remove the two triangular covers on the front of the vanos units, they are secured with 3 hex bolts. once you remove these it releases the oil pressure in the units and you can slide them away from the heads easily. now you have room to unbolt the pistons from the spline gears. fyi these are REVERSE thread. removing the covers first also allows you to see if the pistons are in assembly position(pistons flush with the ends of the bores). you dont have to remove the spline gears to remove the vanos units.

iirc and correct me if im wrong but i dont think you have to actually remove the units to set the timing.
 

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Great write up, it should ensure that everyone's cams are perfectly timed.

I change a lot of Peugeot 3,0l v6 cambelts (used in the Peugeot 406 coupe-google for a pic if you're interested) and those engines have a similar procedure of locking the cams and slackening the pulley to get the belt's tension correct. If this process is done carefully, it makes for a really nice, sweet running engine; it's a noticeable difference. I'd imagine it's just as important for the M5's engine.

It took me a while to realise that it's only the vanos solenoids and piston covers that are removed.

You have the 'off engine' vanos unit pictures just to illustrate the vanos piston initial position, where the piston is as far 'out' as is possible, I presume.

A few questions:

If, when you've pinned the crank (at tdc on cyl1 and the vanos is at initial position), the camshafts do not align with the slot in the cap, you will need to adjust the camshaft.
Then, you turn the engine over (360deg) to reach the 'bottom three' sprocket bolts and then turn it over again (another 360deg, so a full four strokes) to reach the 'top three' sprocket bolts (thus freeing the camshaft) and also to be able to see how the adjustment is coming along. The camchain will be holding the sprocket in its position-so it will not move.

I presume that the crankshaft will need to be pinned again at this point, to lock the crank and camchain.

Here's my first question: Do the M8 bolts (or 8mm drills) lock the camshaft tightly, offering virtually zero cam rotation, or are they a bit slack, allowing the camshaft to be adjusted a bit? In another way, if the 8mm drill fits, will it therefore mean that the cams are set correctly?

I take it that the camshafts are adjusted with the 8mm drill out, using the 27mm spanner to rotate the camshaft to its correct position.

Second question: I know you've tried to show this in the second picture, I'm just wondering if there's a certain way to determine if the vanos pistons/helical gears are in the initial position? Is there a particular distance that can be measured or would we just allow the pistons/helical gears to retract as far as possible?

nightkrawler, you mention that the actual pistons need to be unbolted from the helical gears, is this really necessary (and also, how easy would they be to refit later on)? I would imagine that the helical gear can retract 'only so far' until it cannot come out any further (due to the vanos unit itself being in the way) and due to the rotating portion of the sprocket possibly reaching the end of its adjustment slot - by retracting the helical gear it is going to be rotating the inner sprocket portion.

Is it also necessary to remove the solenoids? Am I correct in thinking that these control oil flow to particular areas of the vanos piston, thus pushing it inwards or outwards? Wouldn't the oil pressure dissapear over time anyway?

Third question: can the vanos units be set to the inital position using the GT1? I have not looked at the various engine maintenance options in much detail, but since I have this it would be great to be able to set the vanos in this position with it. Would th engine need to be running to do this (ie would it need oil pressure)? The tis mentions the use of air pressure to supply the vanos units, I wouldn't really want to start disconnecting pipes!

Fourth question: is it possible to get the gaskets for the piston covers? Or, do they have any gasket or only use some form of sealant or maybe a re-usable rubber seal?

Lastly, how necessary is this adjustment? Are most engines 'out' after a certain mileage?

Again, thanks for the write up. I'm just trying to get everything absolutely clear in my head before getting on with the job (as I have most of the bits off to reach the injectors, I might as well go the extra mile and check the cam timing, it's not actually that much more work).
 

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Discussion Starter · #11 ·
Nightkrawler,experience shows,that removing the cover of the pistons(which I do),is usually not enough to release the pressure.Hence removing the solenoids.
Piston covers and solenoids away means no need for Vanos tools.
I am well aware how to remove the units without removing the helical gears,see my other write up.
The picture of the Vanos unit removed is only to illustrate the position of the pistons,nothing more.

Ger:

There is no difference using 8mm drill or M8 bolts,the drill is a bit easier to insert as it is a plain surface.
You rotate the cam until the 8mm bolt or drill can lock it,this means timing of this cam is correct set.

To determine the initial position of the Vanos,I used the picture of the removed unit.If it looks like this,the correct position is reached.


DIS is for this not a help,the only thing you can do with it is shut down the Vanos in assembly position,which is different from initial position.

The O-rings for the piston covers are not available from BMW.
A trip to the local car part store is a solution.I know many people do not bother changing them and see never leaks re-using the old O-rings.

To answer the question,every engine I checked it was off(about 8-10 so far)...
They came from the factory assembled with the timing off.It is not enough to trigger Vanos errors as it is within the operation range.
This is also very popular issue on the S54s...

On every engine I did,I noticed the car has more torque in the low rpm than before.I often have cars that produce good peak power,but the lower and mid range is a bit flat(if that makes sense).
 

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Sorry for the rethink.

Should you lock all 4 cams at the same time or only the one you are adjusting?

Also, once the cam is locked with the 8mm rod, if the timing is out because the slots do not align, are you turning another part of the cam using the 27m spanner to align the slots?

I mean, do the 6 locking nuts hold a slip arrangement solid together, and once loosened the shaft part of the cam can still be turned but the "vanos" part of the cam is held by both the chain and the 8mm rod?

Sorry for the barrage of questionss dude, you must feel like i don't know one end of the spanner from the other!!! I assure you i do mate, but i like to go into things as prepared as possible.

Thanks again Raikku
 

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I think that, simply put, the process is:
Set vanos pistons/helical gear to 'initial position.'
Lock the crank at tdc, firing on cyl no.1 .
Check to see if the camshafts are correctly positioned, using the line and gap and using the 8mm drill, if correct, both the lines should align and the 8mm drill should drop in.

If any camshaft is 'out,' it needs adjusting, so it needs slackening. Now, for this you need to see the marks and you need to lock the camshaft/tighten the bolts once its position is correct, so first you need to turn the engine once (one crank revolution which is half a cam revolutuion; remember to remove crank locking pin) to gain access to the bottom three sprocket bolts and slacken them.
Then, you turn the crank once more to come back to the top three bolts and the aligment marks; important to lock the crank now. Slacken the top three bolts whilst holding the cam with the 27mm spanner, adjust the cam's position (and now lock it with a 8mm drill, which will now fit as it's in the correct position) and tighten the top three bolts (cleanig and locktite is also recommended).
Remove the locking pins.
Rotate crank once again to enable you to tighten the bottom three bolts (again, cleanig and locktite is also recommended) and basically, you're done.

It would probably be wise to double check everything before assembling the engine, just to be 100% happy.

I'd say that the cam locking pins do two things, confirm that the camshafts are timed to the crank and also hold the cams when you work on the vanos or timing chain.
 

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Discussion Starter · #17 ·
Of course all cams have to be locked doing the checking and timing process.

If the Drills/bolts do not slip in the holes when checking the timing,it has to be adjusted.
So turn the crank 360 deg clockwise to overlap TDC cylinder 1,lock crank,slacken the 3 accessible bolts per cam,turn crank 360 deg clockwise further to ignition TDC cylinder 1,it is then already possible to turn with the 27mm spanner the individual cams that they line up with the markings and can be locked.After that slacken the rest of the 3 bolts per sprocket.

The connection between the sprocket and the cam is basically the spring force and friction of the diaphragm spring of the cam gears.
 

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Great info Raikku! Another great DIY that is above my level of experience and comfort haha

This can all be done with the BMW tool kit in the trunk right?? :hihi:
 
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