GRiSO timing chain tensioner

…how to check if it's broken/in bad condition?
Symptom is: from time to time an incredible loud ticking noise is coming from right head when engine is hot and runs with low revs (idle to ~2500) e.g. standing at traffic light. Goes away with higher revs and will return days or weeks or even month later once again. Correct if i'm wrong, but tensioner is not driven by oil pressure, isn't it?
How difficult will be a replacement, is this a head off job?

thank you for input

Dietrich

Has your bike been rollerised? If so by whom? The the chains are tensioned hydraulically, there is a plunger that sits with its priming end in a reservoir in the wall of the cylinder. It's quite possible to install them the wrong way round and if the rollerisation was done by someone not big on thinking they may of put it back in arse-about.

It's not difficult to check. Take the tank off and undo the plug over the end of the tensioner and pluck it out. The end with the priming hole goes uppermost, into the plug as it were, as the area under the plug is the reservoir.

If it is in the right way up there may be a problem with the tensioner valve not sealing correctly. A spec of grit between the ball and it's seat would do this, (Or a small particle of shattered DLC off a tappet.). Try working the ball around with a pin while giving it a good wash with carby cleaner or thevlike. If that fails to make any improvement replace the tensioner plunger.

Pete

Pete Roper wrote:

Has your bike been rollerised? If so by whom? The the chains are tensioned hydraulically, there is a plunger that sits with its priming end in a reservoir in the wall of the cylinder. It's quite possible to install them the wrong way round and if the rollerisation was done by someone not big on thinking they may of put it back in arse-about.

It's not difficult to check. Take the tank off and undo the plug over the end of the tensioner and pluck it out. The end with the priming hole goes uppermost, into the plug as it were, as the area under the plug is the reservoir.

If it is in the right way up there may be a problem with the tensioner valve not sealing correctly. A spec of grit between the ball and it's seat would do this, (Or a small particle of shattered DLC off a tappet.). Try working the ball around with a pin while giving it a good wash with carby cleaner or thevlike. If that fails to make any improvement replace the tensioner plunger.

Pete

Hi Pete,

ticking noise symptom showed up several times within the last - hmm - 15.000 Km before AND after bike has been rollerised in late spring last year. The latest noise event was in autumn somewhat 2.000 Km after rollerisation. (It happend while emission testing due annual MOT check and techies gazing at bike and asking me if this is real italian style… )
Roller swap was done by official Guzzi workshop. Normally they are doin it right and they have a good reputation, but they also act sometimes carelessly and did some shit on my bike (e.g. every service they overfilled motor oil… )
I'll do the check as soon as possible and will report. I think it's part no. 20 (21) on the chart:
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thank you for your advice!

Dietrich

Part 20, correct.

Pete,

Am I right with the following...?
To check or change the tensioner from the left chain (nr 21), I have to take of the left cilinder?

I think mine is draining each time after a while (few days) not using my G12.
It's rattling a few seconds when starting the engine...


Here, at my place, it's winter now.
So my G12 has his winter sleep, no salty roads for my friend...
In a month or two, spring will start, this is the time to this kind of work.

Yes. But the fact it rattles for a brief period is utterly harmless. I'd guess some 35-40% of them do it. Both of mine do as do just about every Aprilia V4 ever made and it doesn't do any harm.

Ride more! Worry less!

Pete

Thanks Pete,

I'll leave it as it is...
It didn't worry me to much, I've been riding Harley for over 25 years... they do that too.

Pete Roper wrote:

Part 20, correct.

OK, garage season just began… here is the update:
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Took off the RH tensioner and the only obviously irritating thing is a somewhat "bad fabricated" plug with an eccentric milled hollow inside the plug…
The hollow is 0,5 mm deeper than the rest or the LH plug, which has nothing like this inside(?). Anyhow i'll swap the plugs RH to LH.

"Try working the ball around with a pin while giving it a good wash with carby cleaner… "

Pete, where is the ball to play with? I assume it's inside the tensioner stick and therefore not visible. Is it possible to dismantle the stick?

Dietrich

No need to disassemble the tensioner plunger. Look in the end that sits uppermost towards the cap and down inside the inner *Tube* you will see the ball sitting inside the priming hole. To Leeds the tensioner linger down you have to poke it inwards with a pokey thing of some sort while squeezing the plunger. When the ball is unseated it allows the oil to escape past the ball and will help flush out any foreign matter that may be interfering with its seating and operation.

Pete

Pete Roper wrote:

No need to disassemble the tensioner plunger. Look in the end that sits uppermost towards the cap and down inside the inner *Tube* you will see the ball sitting inside the priming hole. To Leeds the tensioner linger down you have to poke it inwards with a pokey thing of some sort while squeezing the plunger. When the ball is unseated it allows the oil to escape past the ball and will help flush out any foreign matter that may be interfering with its seating and operation.

Pete

OK, here is a feedback: I gave it a try and poke around and there was indeed a tiny tiny little bit of debris coming out of the tensioner… something like a mix of resinlike grain and fluff… hmm.
I don't know it this little dirt had have an influence on seating and operation.
Unfortunately i had no chance to take a snapshot – too oily hands… but i did one of the tensioner with "pokey thing" for everybodys interest:[You must be registered and logged in to see this image.]

I'm curious if chain rattle noise will return someday.

Thank you Pete for input,

cheers
Dietrich

Dietrich,

I am in a similar situation with tensioner suspect No 1, in making loud tappet like noises. So I'm interested to see how you get on.

Not much came out of my tensioner & the noise was there after the engine warmed up, so I have ordered a replacement as it wasn't too expensive.