Chain tensioner noise

Hello everybody,
a mechanic, friend of mine, has several Stelvios (all rollerized) coming over his shop. They all ahve 50-60k kilometeres on the clock and have a noise coming from the cilynder head.
Looks like it's the chain tensioner than cannot push well enough. Usually it's the Rh.

He tried to put a new tensioner but the problem persists.
He was now thinking about worn oil pump (not enough oil pressure) but before spending 500 euros for one he asked me help him investigate.

Is this a known problem?

Is there a known cause?

Is there a known solution?

Thank you!

I think he is looking in the wrong place.

The commonest cause for low oil pressure, which in turn causes the tensioner to not pump up, is the gasket between the sump spacer and the block blowing out around the main front delivery gallery.

The cure is to drop the sump and then the spacer and replace the gasket. Don't use the factory gasket though as it is the cause of the problem. They are thin and frangible and can't compress properly. Instead of that use one of the thick aftermarket gaskets available like this one.

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Although listed as the sump gasket for 1100's it is also the spacer gasket. You will almost certainly also need a sump gasket for between the sump and spacer. That would be this one.

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If it has run like this for any length of time it is probably worth dropping the rod caps and checking the big ends for damage but if he's willing to risk it he can just do the gasket.

Thank a lot Pete.
I'll pass your message and give you some feedback.

Ok,
replaced the gaskets in two Stelvios, 100% success so far. Tensioners (and all the rest) just work properly now!
A big thank you from Hercules, the Guzzi mechanic in Athens - Greece. (seriously, his name is Hercules...)