Strange sound coming from LH cylinder head 8V

[klaas123]

My Griso 8V at 9000km suddenly started making this sound:

http://www.youtube.com/watch?v=YleQa3LQ3mE

Now at 10.000km it has slightly increased in volume, despite my Quat-D exhaust I can clearly hear it when riding at low rpm through town, very annoying.

Importer/dealer say there is no problem with my bike but I disagree and would like to know the cause of this sound.

It is clearly cam chain / cam shaft related, but what is causing this sound and is there a remedy?

 

[mattin]

I have the same noise. Had it very bad, and the Japanese importer changed left cylinder, cylinder hear, cam shaft, chain tensioner, everything that comes with cylinder and the head. That was at about 7000km.
http://www.flickr.com/photos/mattinaskali/4000172418/
I didn't like the change, because now I have half the engine well driven in, and half brand new and rough.
Still I think I have the noise every now and then.
Before the factory recall lifter and cam shaft change, at 2500km, I had bad noise on left side. How ever the cams and lifters were good.
Unnecessary change.

I don't know if BMW's recall has any relation, but they had similar chain tensioner, and as boxer's left cylinder points down when on side stand, their problem was the oil got out of the left tensioner. After cold start there was noise for a moment. Recall fixed it.
Now Guzzi has the left tensioner UNDER the chain, when right is above. So I am thinking that the gravity works against the left tensioner though helping the right one. Another impact is that the left tensioner is very difficult to change when right one would be easy. Excluding the tensioner's cylinder which is bored directly to the cylinder block.

I also claimed oil, as the noise first time came only after the very fist maintenance. Local importer changed to Motul motorcycle oil, which comes with clutch friction and gearbox additives that Guzzi doesn't need. Now I am riding with Castrol 10W/60, but still I feel the noise is very close there bursting out any time. Perhaps I am just too sensitive now....
Hope to learn more about this topic.

- Matti

 

[klaas123]

Thanks for your contribution Matti.
The sound in your engine seems the same but harder, also in my engine it comes at regular intervals.
When my engine is cold the sound is hardly noticeable, how was that in your case?

My bike lost power on one cylinder at 700km, a cam-follower had broken.
Then the recall was done but something went wrong there, when I collected my bike the typical sound of the cam-chains had gone and was replaced by the same sound I have now but a little louder.
I returned the bike after a 25km drive, dealer said there was no problem but upon inspection both cams were found to be blue (had run hot) and were replaced again (after only 25km!)
Now that sound has reappeared but only on the LH cylinder head, the cam-chains still sound "normal".

 

[Penis Rotor]

Oh for fucks sakes....

 

[klaas123]

Oh for fucks sakes....

Tell me more Pete, I want to know..

 

[Penis Rotor]

Look, I'm sorry. That was a bit presumptous but I amd SICK AND TIRED of hearing these problems sheeted home to Guzzi and/or the design team. Yes, Guzzi have always been notorisously tight, and sometimes their tightness has led to problems, (Want me to list half a dozen? I can but it's not worth the arse.)

Thing is the new 8V motor is a GOOD STRONG design. All problems associated with it have been down to two things. Poor service and poor parts supply from cheap-arse suppliers used by Guzzi/Piaggio.

Since the cam issue was addressed by the recall I have heard of a very few instances world wide of further failure on bikes whch had only had the pathetic 'Flush the oil' treatment rather than a full inspection. I have though heard of NO failures in engines that were rectified BEFORE the tappets went tits.

My bike was a prime candidate for the tappet problem and it had the 'Old' design tappets. It did 20,000 or so KM before i got the recall bits and it NEVER FAILED and SHOWED NO SIGNS OF FAILING. Why? Perhaps I was lucky. Perhaps though it was because right from day one I realized it was a new motor that *I* had to LEARN about and onserve closely if I wanted to learn its foibles and failings. I'm not saying there wasn't a problem, there was, soft tappets, but it wasn't the ONLY problem.

The MAIN problem to my mind, and I see it a LOT here too, is simply that the people who are working on these bikes haven't a clue. Really. NO IDEA. and they have no right to call themselves 'Technicians' and are the reason I prefer to be known by my trade name of 'Mechanic'. It may not sound as up-market but at least I know what the fuck I'm doing.

Sorry, I'm convinced that the problem lies in two places. Firstly with 'Dealers' who don't and 'Technicians' who can't and also I'm afraid with Customers who seem to be incapable of doing any research into the product they are buying and whether it is an easy or a *Hard* proposition.

If you want *easy* buy a Harley or a Japanese bike, neither of which will be likely to give any *problems* because either they are able to drop 20% of their power and performance and no ordinary rider would notice or they could drop 20% of their performance and their owners wouldn't care. Guzzis AREN'T hard. In fact they don't come much simpler. They are also strong and robust and SIMPLY EASY! Really, they are! If you're having problems there are two reasons. 1.) You haven't got a mechanic. 2.) You don't really want a Guzzi.

I'm sorry you're having problems, but at the end of the day it is also incumbent on YOU to address the problems yourself the best you can and also to take responsibility for ensuring your rights as a purchaser are upheld. Neither of these things is helped by just having a whinge on the innerneck. The PRODUCT is good, and getting better. The service delivery? Well that is far more three dimensional. Be part of the problem or part of the sollution, but don't just carp and whinge 'cos that really, really shits me.

Pete (Far too old to be having to tell needy children this!!!!)

 

[mattin]

I have the problem Pete described: my Griso was perfect until first service. I am afraid that the wrong oil (most expensive motorcycle oil) the shop used somehow made the chain tightener to operate poorly. I hate the importer causing costs to the factory by changing cam shafts and cam shafts. It seems to me that I have already had 5 perfectly good cams.

Actually I changed oil before let the shop to take the bike, and for a week of 15km rides the noise was gone, but finally returned to the shop. The noise first appeared usually between 3 to 6km ride, that is not when engine was cold, neither when hot. Clearly something to do with oil, okay, the tightener works by oil pressure. Later on the noise started to appear also hot. It appeared between 2500 and 3000 rpm. Now, with changed parts, AND proper oil (Castrol 10W-60), I am half imagine the noise occasionally, but it hasn't really returned.

- Matti

 

[klaas123]

Sorry, I'm convinced that the problem lies in two places. Firstly with 'Dealers' who don't and 'Technicians' who can't and also I'm afraid with Customers who seem to be incapable of doing any research into the product they are buying and whether it is an easy or a *Hard* proposition.

If you want *easy* buy a Harley or a Japanese bike, neither of which will be likely to give any *problems* because either they are able to drop 20% of their power and performance and no ordinary rider would notice or they could drop 20% of their performance and their owners wouldn't care. Guzzis AREN'T hard. In fact they don't come much simpler. They are also strong and robust and SIMPLY EASY! Really, they are! If you're having problems there are two reasons. 1.) You haven't got a mechanic. 2.) You don't really want a Guzzi.

OK, let's clear things up, I was a qualified navy mechanic in the seventies / early eighties and have always maintained/repared/overhauled my own bikes (and those of others).
This was my first ever new bike and it's a great bike.
I want to get rid of this stupid noise and I want to do it myself (screw the importer/dealer/warranty).
So I'm looking for advice on what parts are responsible for it so I can replace them.
No Japanese/Harly shit for me, thanks!

@Matti
My bike runs on full synthetic Agip 10w60 from 5000km (I don't know what they threw in before that).

 

[klaas123]

Although there is a connection between the recurrence of the sound and the engine's rpm the 2 are far apart, leaving a vibration of the cam chain as a probable cause??

English is not my native language so these technical things are sometimes hard for me to explain, my apologies for that.

 

[Penis Rotor]

OK, let's clear things up, I was a qualified navy mechanic in the seventies / early eighties and have always maintained/repared/overhauled my own bikes (and those of others).

Right then. So you know that the first step in using the internet to source information is to;

1.) Do a search.

2.) Filter the information to get rid of the dross and the 'Me-Too'-ists

Top end noises on the 8V motor have been limited, so far, to the early cam failures due to soft tappets and in a few cases a 'Ticking' noise caused by excessive end float and/or poor machining of the rocker carriers and cam-boxes. There have so far been no reported problems that I know of related to the cam chain tensioners or the hydraulic plungers that control the blades.

So, having established to YOUR satisfaction that neither of the KNOWN issues are what is causing this noise, (One assumes you've removed the cam boxes and inspected them?) you have to go back to 'Mechanics 101'.

You start taking things to bits. You inspect them using your eyes, by touch, by feel and by smell looking for any hint of what might be causing the problem. If that fails to show anything up? You get out your measuring equipment and your manual and you start measuring shit and comparing it to other bits of shit until you find which is the shitiest bit of shit and you throw it to the shit-house and install a new bit of shit that's the right size.

That's what mechanics do. That's our job. If you're a mechanic you should know that. There is going to be no sudden bolt from the blue that is going cure this problem. First of all its got to be identified, then its got to be fixed. Both of those of course depend on whether there is a problem in the first place! The 8V motor IS Noisy! Mine sounds like a cement mixer full of bricks at the best of times. In warmer weather its worse! It's just the way it is. If I didn't want a noisy bike I wouldn't have an 8V Guzzi. My Mana is whisper quiet and most other modern bikes are similarly silent. I like the racket, I wear ear plugs and its quite acceptable but its part of the character of the bike.

Establish whether yours HAS a problem by comparing it to a selection of other machines. If you decide it does then get stuck in and cure it, or find a shop with a competent mechanic who isn't afraid to get his hands dirty and get hinm to cure it. Just cut the bleating and whining.

Pete

 

[klaas123]

1.) Do a search.

Why do you think I'm posting here???

Just cut the bleating and whining.

Bullshit, but thanks anyway.

 

[john zibell]

OK, let's clear things up, I was a qualified navy mechanic in the seventies / early eighties and have always maintained/repared/overhauled my own bikes (and those of others).
This was my first ever new bike and it's a great bike.
I want to get rid of this stupid noise and I want to do it myself (screw the importer/dealer/warranty).
So I'm looking for advice on what parts are responsible for it so I can replace them.
No Japanese/Harly shit for me, thanks!

@Matti
My bike runs on full synthetic Agip 10w60 from 5000km (I don't know what they threw in before that).

Ok start wrenching. I listed to you sound bite. Pete has pointed you in the direction of the rocker boxes. I believe that is correct. The sound you are getting is not from the chain. Check the end play on the rockers. They will move around significantly. If you can move them around they will make noise. For the old two valve heads Stan Fridus used to make solid spacers to replace the spring just to get better motion with no end play in the rockers. You may need to replace the rocker box if the opening is too wide, or do some shimming, the choice is yours. If still under warranty, I'd look into your dealer taking care of the issue.

 

[klaas123]

Ok start wrenching. I listed to you sound bite. Pete has pointed you in the direction of the rocker boxes. I believe that is correct. The sound you are getting is not from the chain. Check the end play on the rockers. They will move around significantly. If you can move them around they will make noise. For the old two valve heads Stan Fridus used to make solid spacers to replace the spring just to get better motion with no end play in the rockers. You may need to replace the rocker box if the opening is too wide, or do some shimming, the choice is yours. If still under warranty, I'd look into your dealer taking care of the issue.

Thanks John!
The end play on the rockers is huge and moving them from side to side produces a sound similar to the rattle in my video.
Tonight I will measure the end play and post the results, now have to go to work.

 

[klaas123]

For good order I want to say I highly respect Pete Ropers knowledge and contribution to this forum, but sometimes...

 

[Penis Rotor]

OK, now we're cooking with gas.

Measure the end float using feeler gauges at the top end betwixt the pushrod ed of the rocker and the cambox/rocker pivot and report back. Press it up from the *Outside* and stuff a few gauges in and tell us what you find.

Pete

 

[Phang]

Interesting discussion, here is a little visual aid from me.

thumb on the red arrow direction and measure “A”?

 

[klaas123]

Thanks guys, will post my findings this evening.

 

[johnno]

For good order I want to say I highly respect Pete Ropers knowledge and contribution to this forum, but sometimes...

hes a one off,it must be fustrating for him sometimes.Look forward to reading findings

 

[mattin]

Klaas, in your case the noise is so rhythmic, that it has to be connected to some mathematical ratio, like the length of the chain and the size of either the gear at cam shaft or at auxiliary shaft. But I don't understand how The gears don't suddenly become elliptic, nor should he chain be harmed inside the engine if it was not somehow bent during the cam change. But then the noise should have been there long time ago. Sorry for throwing stupid ideas... just hoping to feed more capable brains some seeds of thoughts

BTW, I was also a mechanic in air force. Or kind of. Electronics assistant mechanic. After the army I bought my first Guzzi. 1973 GT, six years old that time... http://matti.naskali.net/bike/Bike.html

- Matti

 

[klaas123]

Measurements:

LH cylinder
inlet 0,3 mm
exhaust 0,2

RH cylinder
inlet 0,25mm
exhoust 0,3mm

So nothing special I suppose.
By feel it seems much more but that is obviously not correct.
Although when moving the rocker shaft up and down it sounds like the rattle I hear when the engine is hot but so will any metal to metal contact in that region.

I have to agree with Matti, the freqency of reoccurance is constant but does not directly relay to the RPM's of the engine, it's much more slowly, let's say every 20-30 revolutions (wild guess) of the cranck shaft.
Could it be a loose/damaged cam chain and/or a problem with the tensioner?