loud tapping noise

[2or4strokes]

 

Hi ever helpful guzzi owners.

 

Went for a ride on the weekend and push my sports 1100i as usual to 220km. Prior to this my fuel pump was intermittent and sometime the bike cannot start which is solved by a good whack on the pump. After this ride I noticed a loud tapping noise from my right cylinder . I took out the valve cover and noticed that the valve clearances are in order and even after closer inspection can find nothing wrong. Even did a compression test and found out that all is in order. I read elsewhere that the 97 sports 1100i can have a "soft cam" which can wear and I hope this does not happen to my bike. For goodness sake the mileage is only 1700km. The bike still starts idle and run normally except for a very loud tapping noise which seems to come from all over the bike but if listened carefully seeems to be from the right cylinder. My Mechanic is stumped as well.

 

Any ideas what could be the problem and if it is in the cam how can I find this out without stripping the engine apart? If it is the cam where can I find a stronger one with all the cam followers sold together?

[gstallons]

If the valve clearance is correct the lobe of the camshaft is not worn either. Correct? I have not seen a piston for this bike but it sounds as though you have broken a piston skirt. The cylinder is easily removed to inspect the piston for a crack or missing sections. You don't need to ride this and find out the hard way!

 

p.s. the skirt is the section that is below the piston pin and perpindicular (sp) to the pin. this skirt keeps the piston straight in the cylinder bore.

[emry]

Dropping the oil pan would quickly answer those questions. The pistons are visable from below and if any mechanical damage had been done you would find it in the screen.

[motoguzznix]

If the valve clearance is correct the lobe of the camshaft is not worn either. Correct?

Not correct

Valve clearence ist not measured at the lobe but on the basic circle of the cam. So even the lobe is worn severely the clearence might be unaffected.

 

But checking the piston is worth the effort. If the cylinder is dismounted, pull the cam followers too and check the cam below. Usually the right exhaust valve is the first to wear. The slightest flat or edge on the lobes makes the cam ready for the scrapeyard. In that case, I would opt for an aftermarket replacement as there are a lot of good choices available:

 

In Germany Dynotec, HTM, HMB

In UK raceco

In US megacycle

In Italy Bruno Scola

[moscowphil]

A few thoughts:

(1) it's true that checking valve clearances won't show if the cam lobe is worn. However, I can't see how a worn cam lobe would produce a mechanical knocking, so I doubt this is the problem.

(2) Are you certain the noise is mechanical, and not caused by pre-ignition? This can sound confusingly similar to a mechanical knock. Check the condition of your plugs for any obvious signs of this before you start pulling anything apart.

(3) Are you sure the noise is coming from the RH cylinder? A loose timing chain can also make quite a bit of noise.

(4) One you've ruled these out, I'd be inclined to pull the head and barrel. That way you can check everything properly - i.e. check condition of piston, rings and bore, and check for play in big end bearing and small end. Stripping the top end of a Guzzi is very easy to do, so worth the effort.

[Greg Field]

If it's a loud, metallic noise, I'd suspect rod bearings or a worn tappet or cam. Also, have you checked for an exhaust leak where the header joins the cylinder head?

[Anders]

I would hope for that.I kind of had the same sound from the right hand side,but discovered it was a really small exhaust leak between the joints in the exhaust.

Anders

[2or4strokes]

Thnaks guys for the feedback.

 

I was hoping it is something not so serious but based on the feedback it looks bad. If it is the cam how can it wears out at such a low mileage. Anyway the bike feels that it has not lost any performance when I rode it back with the loud metallic tapping sound.

 

Is there a chain tensioner for the timing chain?

 

If I do buy a replacement cam which one is the best to go for for fast road use? Similar specs to the standard or one that has more lift?

 

I always thought these engines are reliable so how can this happen? I use good oil , warm up the bike throughly, and maintain the bike very well. The way it revs only seems that it is truly run in since I subscribe to the theory of running in for only a thousand kilometres. Anyway My copa italia with also 5000 kms has been ridden in the same manner and no problems at all.(till now that is)

 

Oh i also forgot to mention that I am running a Will Creedon Chip and have a full termi exhaust system. I doubt it it pre iginition as mentioned by MoscowPhil.

 

questions qustions question when I have so much problems.

[gstallons]

That's life...

[raz]

I had really strange and alarming sounds from my engine (a Sporti mind you) that took forever to diagnose. It was almost impossible to tell the origin and I was pretty sure it came from the timing chest. It ended up just being an exhaust clamp (at downpipe/crossover) banging against the sump.

[2or4strokes]

Hi Guys

 

Just an update on the bike. Removed the oil sump and found a little steel or aluminium grit in the oil. Not sure whether something is broken or worn or whether this is normal running in particles. Bit by bit the mystery deepens on what is the cause for a healthy engine having this problem. Oil is new and has only run about 200 kms.

 

My mechanic says maybe using mineral oil is not suitable for this engine. I don't subscribed to this theory though and will keep you guys updated. Maybe this bike cannot be ridden that hard. does all this make sense ?If the cam is worn as what some of the guys mentioned I will look for the oil comapny that provided me the oil. To be fair i should not mentioned the brand now since everything is premilinary.

[luhbo]

... Just an update on the bike. Removed the oil sump and found a little steel or aluminium grit in the oil. ...

 

How about taking a picture or two of the bits and show them here?

 

Mine actually has nearly 90.000 km on the clock, it's seen nearly all types of oil, sometimes even mixed and sometimes at low levels only, and I'm a big fan of volunteering, high reving Guzzi engines. It means you can be sure that none of your theories so far are reasonable, at least it's not that you should say a Guzzi couldn't stand this or that.

 

Unfortunately quality tolerances might be kind'a different thing, of course

 

Hubert

[raz]

I start to think Greg's more expensive alternatives seem likely. And I agree with Hubert so I'd guess the problem was more related to pressure than quality of the oil. Anyway I guess you need to tear stuff apart.

 

Is the oil filter still tight? And the over pressure relief valve too? You never saw an oil pressure warning light? The latter won't warn until pressure is reeeally low though. What oil level did you have?

[2or4strokes]

I start to think Greg's more expensive alternatives seem likely. And I agree with Hubert so I'd guess the problem was more related to pressure than quality of the oil. Anyway I guess you need to tear stuff apart.

 

Is the oil filter still tight? And the over pressure relief valve too? You never saw an oil pressure warning light? The latter won't warn until pressure is reeeally low though. What oil level did you have?

 

 

Yes the oil filter is still tight and the relief valve seems ok. Never did see any oil pressure warning light at all. Oil level is normal as per the dip stick and somewhere in between.

 

As mentioned this is a very low mileage machine that has been well catered for. Anyway engine will be stripped I guess.

[2or4strokes]

How about taking a picture or two of the bits and show them here?

 

Mine actually has nearly 90.000 km on the clock, it's seen nearly all types of oil, sometimes even mixed and sometimes at low levels only, and I'm a big fan of volunteering, high reving Guzzi engines. It means you can be sure that none of your theories so far are reasonable, at least it's not that you should say a Guzzi couldn't stand this or that.

 

Unfortunately quality tolerances might be kind'a different thing, of course

 

Hubert

 

 

Hubert

 

I guess you are right to say that I should not say that guzzis cannot be ridden hard. Guess I am disappointed this has to happen to a fairly new engine and such things do not happen on any other bikes I have inclusive of Jap and Italian machines. Thats why I am asking is there such a thing as a poor quality cam produce in certain batches because i seriously doubt it is the oil.Or is there any other quality issues from the factory for this year model.

 

Seriously as much as I love guzzis you cannot say they produce the most reliable bike of the lot.