Valve shims, strange surface

neger

New Member
Messages
21
Today I changed the timing belt, and checked the valve clearence,I recognized that some of the valve shims have a strange surface? Is it an issue? Should I change them? 55531
 

Rex B

Junior Member
Messages
542
Looks like the hardened surface is failing and is pitted l would change these otherwise it will wear the camshaft.


Rex B
 

CatmanV2

Member
Messages
30,309
Looks like the hardened surface is failing and is pitted l would change these otherwise it will wear the camshaft.


Rex B
Surely if the hardening has failed, it'll not wear the cam? The Cam will wear the shim (quite fast) I'm just curious here, not disagreeing in any way.

C
 

alfatwo

Member
Messages
4,298
On old Alfa twin cam engines when the cam wears it also takes out the cam followers too, much the same as in a 3200 Maser engine

Dave
 

boomerang

Junior Member
Messages
277
Still an intriguing question, mentioned this problem myself earlier;


I tend to think my cars problems where caused in its past, wrong oil, wrong or lacking service.
Cam shaft journals where fine by the way.

Curious to hear about this cars history regarding oil grade / change etc.
Cam lobes will have suffered already I am afraid, and valve train will be/get noisy to.
If the cams look good, you could try and turn these shims and see what happens then.
 

neger

New Member
Messages
21
I use selenia racing, bought this car 3 years ago drive around 3000km in a year and change the oil every year, the car has 170000 km-s pretty good history. Ok i will change or turn the shims and hope the cams are ok.
 

Rex B

Junior Member
Messages
542
Mine had 2 shims changed some years ago because the hardening was failing. It will not knacker the cam for straight away but your valve clearances will quickly go out of tolerance and all those bits of metal will get around the engine, change the worn ones and your will be fine.

Rex
 

Oneball

Member
Messages
1,445
I use selenia racing, bought this car 3 years ago drive around 3000km in a year and change the oil every year, the car has 170000 km-s pretty good history. Ok i will change or turn the shims and hope the cams are ok.
Don’t turn the shim, you’ll just put the disintegrating surface into contact with the bucket, get some new ones.
 

boomerang

Junior Member
Messages
277
The shims only rest at the outer edge on the bucket, the worn surface will not touch anything.
But if hardening is the problem, follow the advise from Oneball.
Interesting to read this is a problem of insufficient hardening.
 

Oneball

Member
Messages
1,445
The shims only rest at the outer edge on the bucket, the worn surface will not touch anything.
But if hardening is the problem, follow the advise from Oneball.
Interesting to read this is a problem of insufficient hardening.
On the photo it looks like the cracking/breakup of the surface goes all the way to the edge of the shim.

You can get the shims from Maserati, Eurospares etc, you’ll need to measure the required size.
 

spacecadet

Member
Messages
325
Tip of the the lobes are mostly ok, there is minor wear on the sides, where the biggest area touches the shims. This could be material pickup from the shims, which would explain why there is no wear further up on the lobe.
 

MRichards

Junior Member
Messages
107
My first reaction was to the buildup of varnish caused by overheated or substandard oil. That yellow gunk should not be there.
 

neger

New Member
Messages
21
I bought the hills shim removal tool, which worked for me on the exhaust side but not on the intake side, I can't see why, but the shims doesn't fit out, because of the head screw. Is there something I do wrong(surely is:)) I attach some photos.
 

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MUC3200GT

Junior Member
Messages
112
As far as I remember there are some shims which needs loosening of the camshaft before they come out

EDIT: Found it again on the German Forum: two shims on the right banks intake side have been experienced to need loosening of the camshaft by 1..2 millimeters before they come out . There is also expressed the suspicion that those two shims are sometimes "forgotten".
 
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Boomerang_GT

Junior Member
Messages
147
It was the two shims on the right bank front intake for which to unscrew the camshaft.
But for some others you need to remove the bolts of the upper camshaft housing.
I don't believe its necessary to unscrew all at once and tighten them in this special order, but that you can safely remove one at a time. Tighten them with 2,5kgm.
And check the valve pair text to that screw so you don't have to do that twice.
In general it makes a big difference how thick the shims are. With shims above 3mm, they will more likely make troubles getting them out. With shims under 3mm, they go out more easy.

Btw: How does the cam shaft head looks at this worn out shim?