Technical M tappets again.....sorry

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Technical M tappets again.....sorry


New member
Oct 2, 2007
Hi everyone

Just took the cover off and measured all my gaps.....rangin from about .5mm to 1.1 mm over the 8 shims. Just wanted to know if anybody has a tip off changin the shims without removin the cam? or is there a special tool for the job. Asked my local dealer but no help there. First time fiat owner an not impressed with our dealer freinds at all.....:mad:

Thanks all

You can change the shims with the cam still fitted AFAIK but its fiddly - it would be easier to remove the cam IMO.
If some are upto 1.1mm then that is a huge gap, there is a possibility that the cam is worn and that may need replacing.

But as for swapping shims, its easier to remove the cam if you are doing then all
I was wonderin if maybe the gaps are so much because whoever had the car before me changed the head gasket and had the head skimmed and just rushed grindin the valves or somethin:confused:. as oppose to the cam bein worn cause it seems to measure the same across all 8 cams.

thanks all
If the dimensions of the lobes are the same then it might be OK, but do check end to end as well as base circle, and use a micrometer.

Regrinding valves should sit them further into the head closing the gaps, unless new inserts were fitted.

Sounds strange to me, but you might as well try the shims, they are not too dear.


Thanks mate

am i best goin to fiat for the shims i have written the gap sizes down do I just call them with the sizes and they give me the appropriate shims that just to easy?

Thats way to easy. You've measured the gaps, thats a start.

Now, take the existing shims out and measure them, don't reply on any markings on them, actually measure them.

Then do the sums based on the total distance twixt bucket and cam, and allowing for the appropriate clearance, calculate whether any of the shims you have will work in a different position.

After that, you will know what you require to order from Fiat.


Thanks D

You know your stuff (y). Thanks for the advice i will get it sorted sooner or later just findin the time and gettin it offa the road (for the first time ever my missus an I are arguin over who is drivin).

Oh well will get on with measurin the shims and then call the very helpful people at fiat:bang:. The worst thing about ownin a fiat is fiat most unhelpful dealers ever.

Thanks again D