service reveals some issues - FIXED :-) no further issue.

[Redish]

valve seat regression on a 12k miles engine ?? nahhhh.... too unlikely ,

Like I wrote before: if there is now too little room for the follower to slide away (to get the shim out), how did they get the follower sliding in last time?
Think about that :wink: :roll:

If the follower is stuck, that means that it's over 0,2mm out of spec compared to the other ones, which is a lot, also compared with the other ones.
Also, it's the back of the engine that needed adjustment (cyl 4-6), and that is the part of the engine that usually gets hottest. I don't know if that's common on a s54 but it is something I noticed.
I looked at the drawings and the s54 doesnt have seperate lower bearing caps or a lower bearing ledge so you probably cant measure relative valve stem hight with a straight edge like I suggested before (that would easily diagnose the real problem).
I guess the cam lobe sits lower than the bearing faces from the cam.

If the shim in there is of a normal size (according to the video somewhere around/between 2.34 and 2.24) I would get to the bottom of this.

What do redish advise?
From what I understood in their post they'll get the cam out anyway.

At this stage, with this miles, knowing there is probably nothing wrong with the other 'becoming-common' S54 problem of head gasket splits, we wouldn't suggest rushing into 'head off' scenario straight away.

Although it's not the correct thing to do, there is potential to depress the spring (as I mentioned before), to allow a temporary clearance to slide the follower out of the way.
We're quite against this as nobody would want to press on the upper valve spring plate for fear of damage/deformation, and therefore if you pressed on the valve spring itself, there is a possibility the spring with compress, but valve stay still along with the upper spring plate, causing a clearance gap between the upper spring plate at the valve collets which are only held in place by pressure of the upper valve spring plate. If one of these 2 collet halves move or worse fall out, it immediately turns ugly.

So the only professional approach to this fairly uniquely documented problem, is to remove the Vanos unit (which is harder on the E85/E86 chassis due to the front panel location compared to the E46 chassis, and remove the chain tensioner, upper chain guard, remove inlet helical gear, remove inlet vanos gearbox hub, remove inlet sprocket, then remove the inlet camshaft.

That will allow obviously clearance to slide the Inlet 5 Left rocker finger, remove the shim in question, and start measurements and investigation.
We would probably put the smallest shim BMW produce back in to start with. Install the camshaft, check clearance immediately without rotating the engine.
If all is well and there is clearance, then continue to build the valve train and Vanos system up to allow the engine to be rotated.
Then start the task of working our way through the feeler gauges and finding the shim that will allow a mid-range clearance of 0.20mm.
Once we know which shim this is, then we can discuss further and decide how safe this method is, and if it should be continued to be investigated (depending on findings).

But getting the cam out is no big deal I think. Should be no more than 1-2 hrs work or so incl vanos.

Just to confirm for everyone, BMW's KSD shows their 'book time' to be just shy of 5 hours labour for removing & installing 1 camshaft:

Hope that helps,
James

 

[srhutch]

With the camshaft removed do you think you can get any meaningful measurements of the the valve stem length to see if there is any regression. I know we are talking microns so this I think would be hard to do.

Is there a chance that you will find something has dislodged or isn't sitting correctly?

 

[Z4M-2006]

What do you actually think has caused the problem James..?

 

[GuidoK]

Just to confirm for everyone, BMW's KSD shows their 'book time' to be just shy of 5 hours labour for removing & installing 1 camshaft:

So I'm pretty accurate with my estimation to just get the cam out . (getting it in again is about as much work obviously). the valve cover is already off :wink:
It's not that different from the m54 I have I think. Getting the vanos off (not documented by TIS on the m54) and figure out a way to align the helix gears on my schrick cams (also not documented by bmw...) were my biggest worries.

is to remove the Vanos unit (which is harder on the E85/E86 chassis due to the front panel location compared to the E46 chassis,

On the z4 m54 you need to drop the engine on the subframe to have the vanos clear the front panel (as I had to figure out). I don't know if this is necessary for the z4m or if there's enough room (the m54 vanos hangs on very long threaded studs).
Still an easy thing to do though.

I'm interested to see which shim is underneath and by how much that valvestem came up compared to the rest.

 

[Beedub]

If your engine didnt look like that at 12000 miles after 6 (guess) oil changes then i would be worried...lol..

So do you think Simpsons simply didnt check the valve clearances due to the low miles,or just happened to miss out this one that has a problem ?

Has the valve clearances only been checked once before in its lifetime ??

Remember if the cam lobe or shim wears the clearance will get bigger,valve seat wear will make the clearance get smaller..

im not sure and I'm not letting this thread get into a this that or the other... BUT...... simpson and i need to have a conversation monday for sure... either this issue present itself within 2k miles..... or simpson didn't check properly / simply went at it with a looser attitude due to the condition of the engine, miles, whatever.... Now if we was seeing this one more than 1 valve then id say ok, something going on here... Until we crack it open and get that shim out, we won't know any further.

and I've seen the internals of my moms m6 drop top back when it has 15k miles on it and my own vehicles that I've messed around with.... it looked NOTHING like this inside so no i actually don't agree with you at all, so maybe a combination of over servicing , and high oil temps ( i stop pushing at a certain point and let it cool down but I've run it to that point quite a few times ?? Or could simply be as you say, new looking low miler.

on the servicing i went back to check this to be 100% accurate, the car has had 2 inspection2s ( including this one ) and around 6 (include the official ones ) oil services, all unofficial done by myself, it is very much over serviced. so the last inspection 2 or the first one for the car was at simpsons.

rest assured ill keep posting up and posting pics in this thread car won't go back till december-ish however, got a big office move coming up that needs my attention, plus my son is struggling to settle at school and that also needs my attention and tbh, thats more important than anything to me right now.

 

[Beedub]

valve seat regression on a 12k miles engine ?? nahhhh.... too unlikely ,

Like I wrote before: if there is now too little room for the follower to slide away (to get the shim out), how did they get the follower sliding in last time?
Think about that :wink: :roll:

If the follower is stuck, that means that it's over 0,2mm out of spec compared to the other ones, which is a lot, also compared with the other ones.
Also, it's the back of the engine that needed adjustment (cyl 4-6), and that is the part of the engine that usually gets hottest. I don't know if that's common on a s54 but it is something I noticed.
I looked at the drawings and the s54 doesnt have seperate lower bearing caps or a lower bearing ledge so you probably cant measure relative valve stem hight with a straight edge like I suggested before (that would easily diagnose the real problem).
I guess the cam lobe sits lower than the bearing faces from the cam.

If the shim in there is of a normal size (according to the video somewhere around/between 2.34 and 2.24) I would get to the bottom of this.

What do redish advise?
From what I understood in their post they'll get the cam out anyway.

At this stage, with this miles, knowing there is probably nothing wrong with the other 'becoming-common' S54 problem of head gasket splits, we wouldn't suggest rushing into 'head off' scenario straight away.

Although it's not the correct thing to do, there is potential to depress the spring (as I mentioned before), to allow a temporary clearance to slide the follower out of the way.
We're quite against this as nobody would want to press on the upper valve spring plate for fear of damage/deformation, and therefore if you pressed on the valve spring itself, there is a possibility the spring with compress, but valve stay still along with the upper spring plate, causing a clearance gap between the upper spring plate at the valve collets which are only held in place by pressure of the upper valve spring plate. If one of these 2 collet halves move or worse fall out, it immediately turns ugly.

So the only professional approach to this fairly uniquely documented problem, is to remove the Vanos unit (which is harder on the E85/E86 chassis due to the front panel location compared to the E46 chassis, and remove the chain tensioner, upper chain guard, remove inlet helical gear, remove inlet vanos gearbox hub, remove inlet sprocket, then remove the inlet camshaft.

That will allow obviously clearance to slide the Inlet 5 Left rocker finger, remove the shim in question, and start measurements and investigation.
We would probably put the smallest shim BMW produce back in to start with. Install the camshaft, check clearance immediately without rotating the engine.
If all is well and there is clearance, then continue to build the valve train and Vanos system up to allow the engine to be rotated.
Then start the task of working our way through the feeler gauges and finding the shim that will allow a mid-range clearance of 0.20mm.
Once we know which shim this is, then we can discuss further and decide how safe this method is, and if it should be continued to be investigated (depending on findings).

But getting the cam out is no big deal I think. Should be no more than 1-2 hrs work or so incl vanos.

Just to confirm for everyone, BMW's KSD shows their 'book time' to be just shy of 5 hours labour for removing & installing 1 camshaft:

Hope that helps,
James

james ill be calling you within the next week with a view of getting the car back upto you on a trailer so we can PROPERLY remove the vanos and start by putting a thinner shim in and see where we go, i don't work with the quick way of doing things, not on this car, never have never will, ...... If we do that and next year the tolerance has tightened again i will be coming back with a state 3 VAC head and going for a straight swap at that point. This way I'm putting alittle into the investigation side of things but if i have to crack the head off, ill be going nuts at that point and building back up to serious spec. This car is very very special to me as your guys and yourself can clearly see, this isn't even a blip in my love for the old girl. Its all very interesting however and may be of use to some of the members in the future. Whatever it is, its not a common s54 issue, boosted or n/a.

I've just cleaned her, and she now has hardtop back on and tucked up ready for the next part of our journey




on a side note the gearbox feels so much nicer with the fresh oil, can't believe how much better it feels.....

The engine ( although not being run for long but I'm having work done at the house so its moving around alittle) is absolutely as smooth as its ever been, I'm going to whip the cam cover off in the meantime and do some of my own fact finding and learning for myself so I'm going in alittle more educated.

 

[Ewazix]

Thinking that the unique factor in this scenario is forced induction surely you MUST be looking for a blower-related reason why an inlet valve seat would regress at such low mileage or cause valve stretch/tulip. An interesting piece on why a blower engine may need uprated valve springs to prevent the inlet valve 'floating' open on the reduced air pressure differential at high revs. Float would prevent proper seating (which transfers heat out of the valve) and allow rapid combustion degradation of the seat which is otherwise pretty rare on an inlet valve.

http://magnumpowers.com/valve%20springs.htm

 

[exdos]

Although it's not the correct thing to do, there is potential to depress the spring (as I mentioned before), to allow a temporary clearance to slide the follower out of the way.
We're quite against this as nobody would want to press on the upper valve spring plate for fear of damage/deformation, and therefore if you pressed on the valve spring itself, there is a possibility the spring with compress, but valve stay still along with the upper spring plate, causing a clearance gap between the upper spring plate at the valve collets which are only held in place by pressure of the upper valve spring plate. If one of these 2 collet halves move or worse fall out, it immediately turns ugly.

James

James,

Since this problem seems to be almost unique I can understand your reluctance to do what you consider to be a bodge job. However, if the problem were more common, then I'm sure someone would have already produced a special tool which would compress the spring sufficiently to permit removal of the tight shim.

Looking at the parts, those spring plates, as in the photo below, look to be more than simple pressings from sheet material so would it not be possible to make some device which had a rubber surface which would contact the exposed upper spring plate but leaving a hole on the centre for access to the shim, and which would depress the spring by turning a screw (think modified G-clamp which could be attached to fixed points on the engine) just sufficiently to remove the shim so that the opening and closing pressure on the spring could be controlled so there would be no chance of any of the parts being fired out under spring pressure? The spring pressure can't be that great so a rubber contact surface couldn't do any damage.

Not trying to teach anyone to suck eggs, I'm just trying to be imaginative.

 

[Beedub]

you know what f**k it , I'm going to say what I'm thinking..... i could be wrong.... but i don't think simpson ever even cracked the cover off the head. Something that day just maybe didn't go to plan.

why do i think that??? simpson checked the clearances and told me " no shim's needed" then to be precise 1950 odd miles later we have ;

lets look at what redish found , the back 3 cylinders so 5 inlet valves are tight and need adjust UP to the tolerance, the front 3 uniformly ok.

the exhaust looks uniformly ok but on the loose-ish side....

so what we saying here is basically 5 inlet valves have TIGHTENED in 2k miles??? no way...., absolutely don't believe that.... i think this is how the car has come from the factory. i could be massively wrong, but we are all just shooting the breeze now with some a one off anomoly their is hundreds of thousands of blown s54s and trust me the weak spot isn't the valves or head we know exactly where the weak spots are, EGTs, AFRs are on the nail, whatever the reason or cause will be found out but something just isn't ringing right here, the car has run and IS running exactly the same as it always has, the condition of the engine itself is clear to be seen.

simpson did my last inspection 2 with the vt2-500 upgrade so ALOT of work on that particular visit and I'm looking at the results proved by redish, I'm looking at the uniform results wether tight or loose and alarm bells are ringing... now i can never prove or disprove but something isn't adding up for me. I'm not going to ring them accusing them of anything, theirs no point now, I'm going to be asking some key questions and get their opinion, but usually in life if something doesn't add up, its usually not true, and you live and learn, they are good people but sometimes, s**t happens.

id HOPE I'm wrong. but ill never know, and this is further speculation, i can only go with my gutt feeling.

my father has been a master tech for ford for 20 years, worked with denish welsh as his apprentice and i got very angry with him when all this first came to light, As the FIRST thing he said when i showed him the sheets, the video and previous inspection data / current tolerances.... "simpson have never done those clearances". Again i could be wrong but i agree..... the results were too linear across the cylinders, although 5 too tight still, it was still uniformly tight with the other 4 back inlet valves.

i think we will swap that shim and i think it will never tighten again, or not at least within the next significant mileage marker.

 

[Beedub]

And on that note.....

guys, redish , really enjoyed the discussion, and keep the theories and ideas coming...

Redish, ill be back with you very soon, and will give you a call tomorrow to get a date booked, hopefully you mind me being around while we do the next stage of investigation.... while I'm their we'll do the vanos too, even though from the pics its may be futile at this point, it looks like new!

 

[GuidoK]

I doubt the car came this way from the factory.

The valve that has no clearance; do you know what that means?
It means the valve doesnt close! and that gets worse when the engine warms up! (valve stem expands)
In the factory this would show at testing the engine. This is very basic and should light up with big red lights on every run in test they do at the factory.

Anyway you have to solve this clearance issue.

Unless there is a very odd&thick shim installed, there is something else going on I suspect.
It can always be a recent occurred problem (problems have to occur at some point, dont they?)

 

[paulgs1000]

This has been interesting reading and takes me back to setting the tappets on my mates GT6 (so you can see where I'm coming from)
I'm no mechanic - and my comment will probably show this but at the risk of being shot down in flames . . . .
Has the measurement been tried again after the engine has been cycled through more full revolutions - would it be worth trying this if not?

I'll get me coat . . . .

 

[Beedub]

I doubt the car came this way from the factory.

The valve that has no clearance; do you know what that means?
It means the valve doesnt close! and that gets worse when the engine warms up! (valve stem expands)
In the factory this would show at testing the engine. This is very basic and should light up with big red lights on every run in test they do at the factory.

Anyway you have to solve this clearance issue.

Unless there is a very odd&thick shim installed, there is something else going on I suspect.
It can always be a recent occurred problem (problems have to occur at some point, dont they?)

, you doubt but do you know for a fact , you like me don't know anything just another speculator on the internet, you could very well be right tbh and i could be widely wrong or whatever variation of what we are saying, we are all just on here making guesses really as its a very rare issue. You , or me for that matter are no expert here, so lets see what comes of the next few stages. WHATEVER happens going forward..... I'm not convinced on a few points, but again I'm just here on the internet speculation like everyone else, what i do know the car has, always has and still is running in rude health and I'm pleased redish brought this to my attention at a point i can easily rectify it.

i have my own course of conversation i will be having in a very discreet manor, as my thought are just that... my thoughts based on what I'm seeing.

 

[Beedub]

This has been interesting reading and takes me back to setting the tappets on my mates GT6 (so you can see where I'm coming from)
I'm no mechanic - and my comment will probably show this but at the risk of being shot down in flames . . . .
Has the measurement been tried again after the engine has been cycled through more full revolutions - would it be worth trying this if not?

I'll get me coat . . . .

me and my father will do so ourselves in my garage and ill video it.

right now, me , anyone here or even redish have a clue what has caused this anomaly. But its an interesting one for sure.

 

[GuidoK]

, you doubt but do you know for a fact ,

Of course I do not know for a fact. For all I know they may have foregotten to test your engine at all at the factory. I wasn't there....

me and my father will do so ourselves in my garage and ill video it.

Be careful not to break the cam when you try to get it out. They're brittle.

 

[Z4M-2006]

It's interesting..

Very interesting, I hope I'm not coming over as overbearing or pushy, I'm interested in this from an engineering point of view..
I have seen lots of S54's in bits.. Done cranks, bearings, cams, followers and headgaskets... I have seen a few right clearances, but I have never seen one at such low miles.. There has always been variables in the equation that has made me doubt previous work on the engine.. So yours is a great case in point...

If your mums M6 was in a bad way at 15k miles I would be seriously questioning the servicing or oil quality... I have seen lots of engines under warranty conditions and at super low miles , your engine should look as new.
Baring in mind that an insp2 usually comes up in mid 40k mileage, they are always gonna look a bit off coloured.. Especially if kept to OEM service intervals..


I seriously hope you and james get to the bottom of the problem.. I think only stripping and measuring valve length, spring length and deck height of the valve seat will get you the full tale of what's happened...

Good luck on your search

 

[Beedub]

It's interesting..

Very interesting, I hope I'm not coming over as overbearing or pushy, I'm interested in this from an engineering point of view..
I have seen lots of S54's in bits.. Done cranks, bearings, cams, followers and headgaskets... I have seen a few right clearances, but I have never seen one at such low miles.. There has always been variables in the equation that has made me doubt previous work on the engine.. So yours is a great case in point...

If your mums M6 was in a bad way at 15k miles I would be seriously questioning the servicing or oil quality... I have seen lots of engines under warranty conditions and at super low miles , your engine should look as new.
Baring in mind that an insp2 usually comes up in mid 40k mileage, they are always gonna look a bit off coloured.. Especially if kept to OEM service intervals..


I seriously hope you and james get to the bottom of the problem.. I think only stripping and measuring valve length, spring length and deck height of the valve seat will get you the full tale of what's happened...

Good luck on your search

ill be changing the shim for a smaller one and doing 3 consecutive shim checks on a yearly basis, any further tightening of the tolerance then i will agree on valve seat regression or a head issue and ill go back with a stage 3 head with oversize inconel valves :evil: :evil: , if it loosens I'm going to keep my thoughts clearly zipped. But ill keep you all posted over the coming changes subsequent shim checks.

 

[AndrewZ4MC]

Sorry to hear this Beedub - glad to hear its getting sorted

 

[Beedub]

Sorry to hear this Beedub - glad to hear its getting sorted

nice and easy direction, low cost , no harm to anything currently. Car runs like a champ, always has, and I'm certain this will be solved easily.

thankyou for the sentiments however. she's tucked up and needs alittle pampering.

 

[Z4M-2006]

Have you had the valve clearances checked at insp1 services as per schedule throughout its life too?
Or just the previous insp 2 previously at Simpsons?