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

[Z4M-2006]

Thats fair enough then......And i do agree about the charger,its not a rare conversion for the S54 but being honest i have never monitered if there has been any problems..


Maybe air leak within the inlet for that cylinder ? bad injector ?

Can a smooth running test be done on any diagnostics you have ?

Valve stretch.......Hmmm,now thats rare and something i have never seen,but again it cant be ruled out. But easily checked when the head is off..

Maybe a weak valve spring ???

How often do you go to Curburough ? I like it there and its a nice run for me,i would love to see your car.

 

[Beedub]

Why havent they got the original shim out and measured it?
It's not that hard I think?
Or is the thinnest shim already in?
There is no info on that paper?

If your valve seat has worn.... that would not be good....

The only other thing I can think of is something is wrong with the drag lever (follower) or the collet not seating properly, but that's unlikely I think.

apparantly they can't without removing the cam which means vanos out, and i was finding this out on collection of the car. if that shim is too big then its an easy fix.

 

[GuidoK]

That's a bummer.
so with removing the follower the shim can't pass the cam lobe?
That is very strange as it also wouldn't be able to get in if the valve tolerances would be the same...

 

[Beedub]

Thats fair enough then......And i do agree about the charger,its not a rare conversion for the S54 but being honest i have never monitered if there has been any problems..


Maybe air leak within the inlet for that cylinder ? bad injector ?

Can a smooth running test be done on any diagnostics you have ?

Valve stretch.......Hmmm,now thats rare and something i have never seen,but again it cant be ruled out. But easily checked when the head is off..

Maybe a weak valve spring ???

How often do you go to Curburough ? I like it there and its a nice run for me,i would love to see your car.

depends on how many holidays i have a year!! lol....

could literally be something as small as the spring, but sadly the investigation work will be so costly i feel like just going big. But need to really do some research into things before i committ .

 

[Z4M-2006]

All the shims can be removed without removing the cam ... Or am i reading that incorrectly ?

 

[Beedub]

That's a bummer.
so with removing the follower the shim can't pass the cam lobe?
That is very strange as it also wouldn't be able to get in if the valve tolerances would be the same...

according to these guys no.

this goes beyond my expertise tbh so i just take their word on that. You think theirs a tool to lock to the cam to compress to valve to measure the shim???

this COULD be something really simple but either way the investigation strip down will be costly. I'm actually intrigued now.

 

[Beedub]

All the shims can be removed without removing the cam ... Or am i reading that incorrectly ?

redish told me their wasn't enough clearance to remove that shim and without lifiting the cam slightly, hence vanos out.

 

[Redish]

Why havent they got the original shim out and measured it?
It's not that hard I think?
Or is the thinnest shim already in?
There is no info on that paper?

If your valve seat has worn.... that would not be good....

The only other thing I can think of is something is wrong with the drag lever (follower) or the collet not seating properly, but that's unlikely I think.

apparantly they can't without removing the cam which means vanos out, and i was finding this out on collection of the car. if that shim is too big then its an easy fix.

Hi guys,

A new video is uploading as we speak to explain it in a clearer way.
Give it 20 minutes and it will be easier to understand with this new video we've just recorded

James

 

[GuidoK]

Nice

 

[GuidoK]

this goes beyond my expertise tbh so i just take their word on that. You think theirs a tool to lock to the cam to compress to valve to measure the shim???

I don't know.
If you look at fiat engines etc who also use platelets, they have a spanner that pushes the cup down wherein the platelet lies.
So you compress the valvespring (pushing it down, you wedge some kind of a fork between the cam and the platelet cup) and then you get the platelet out.
But with the S engine you swipe the follower to the side I think and then get the platelet out.
If there is no firm area to push against, the fiat method is no good. On motorcycles they do it in a similar way (they als almost always have shims; high revving engines )

 

[Beedub]

Why havent they got the original shim out and measured it?
It's not that hard I think?
Or is the thinnest shim already in?
There is no info on that paper?

If your valve seat has worn.... that would not be good....

The only other thing I can think of is something is wrong with the drag lever (follower) or the collet not seating properly, but that's unlikely I think.

apparantly they can't without removing the cam which means vanos out, and i was finding this out on collection of the car. if that shim is too big then its an easy fix.

Hi guys,

A new video is uploading as we speak to explain it in a clearer way.
Give it 20 minutes and it will be easier to understand with this new video we've just recorded

James

NIICCEE!!!! we need to talk james so we can throw some ideas around.

 

[jimmybell]

I thought all shims could be done without removing the cam, it's the followers that need the cam out ?

unless is it immovable due to being too tight?

 

[Big Red Cat]

Glad James is delivering the goods for you, and a great video. I know I've banged on about Redish a fair bit on here in various threads but glad you guys can see why I think he's so good

+1
not good news for you but love the video. I'm glad I live close enough to be able to have Redish look after #308

 

[GuidoK]

unless is it immovable due to being too tight?

Indeed maybe the follower is stuck wedged between the camlobe and the shim so they cant slide it to the side (as there is no space between follower and camlobe).
MAybe the next video will show that.

 

[Redish]

Hi Guys,

Interesting discussion, and a first for us to find this total 'lack of clearance' on an S54 out of the probable 100's we've carried out valve clearances on.

Up until this week, there has only been one issue which can stop valve clearances (shim replacement) which has been too much oil contamination and varnishes built up on the valve train - especially the rocker shafts.
This contamination (dirt) can be thick enough to stop the rocker finger from being able to be slid along the rocker shaft (because of the expanded size of the rocker shaft due to contamination build up).
Without being able to slide the rocker finger out of the way, you simply cannot get to the valve shim to be able to remove it.

A little confused why can they not replace the shim with a smaller one?

In beedub's Z4M case this week, a new (first time we've seen it on an S54) problem has been found where the clearance between the rocker finger and the back of the camshaft is non existent (read touching) that the valve spring is compressing the shim and rocker finger up into the back of camshaft.
So there is no way that human forces can move/slide that rocker finger out of the way (to access the shim), because of these compressive forces.
These forces equate to zero clearance on this Inlet 5 left side, and could either be due to the shim being too large (but it would have never been able to be installed in that state), or valve seat wear allowing the valve to travel further up into the head and reduce the clearance between the rocker finger and back of the camshaft.

Yes, any body could use 2 flat blade screw drivers to attempt to depress the valve spring to assist in accessing the shim, but that's not what we're about.

Anyway, here'a brand new video we just recorded to explain it better:
https://www.youtube.com/watch?v=_wMWwSANcR4


Hope this helps,
James

 

[AndyBeech]

Yes, any body could use 2 flat blade screw drivers to attempt to depress the valve spring to assist in accessing the shim, but that's not what we're about.

James

Good to see you on here again James, another interesting video, great stuff!

 

[GuidoK]

Excellent video

But still it's probably the valve seat. Otherwise they (or the one that installed the too thick shim) couldn't get the rocker finger in again :wink:
(or some strange problem with collet/valvestem/spring plate)

So first you get the camshaft off, measure the shim, but I also presume knive edge the whole valvetrain to see if that valve is indeed sticking up? With measuring the shim you still don't know how the clearance is as now it's under tension.
But you'd have to do that with all similar shimms installed I think to get an even reference? Measuring on the collets edge (or valve spring plate, whatever sits highest) probably isn't very accurate.

Unless you find dirt sticking under the shim or follower, but that is not a likely scenario with such a clean and new engine.

But very nice to see you making time for these video's and showing the problems encountered.

 

[jimmybell]

Nice vid - whilst you could remove it with force, it would most likely not expose the cause - and on such a rare issue (on a charged engine) i suspect it'd be wiser to find out what made it tighten. Would be cool to see a video with the cause if/when you get there, mainly out of interest.

Interested to know if there's any wear on the follower finger too, the tolerance for wear on them is pretty fine. If anyone wants a rocker finger for a keyring i have a pile somewhere

Beedub - shrick cams + followers next?

 

[Z4M-2006]

Not good,

I take it that the follower has contact with full 360 degrees of the cam lobe ?

Has it worn the back or the ramps and flanks or the cam ?

 

[exdos]

Beedub, bad news but it seems the problem is definitely in the right hands.

Was the camshaft and Vanos touched at all when the SC was installed? Have any shims been changed at any previous inspections?