Noise which BMW attribute to alternator

mallea

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I have read a lot about the noise's made by the R1200GS. Cam chains, bearings etc. etc. However mine started making a slapping/knocking noise which I thought was going to be something similar. Took it to the shop as it was getting worse and the mechanic sprayed the alt belt with silicone.....noise almost completly gone.

Weekend in the Peaks...noise back to its worst yet.

Back to shop.....new alt belt. (They did not appear to question why a healthy alt belt had been broken in such a short time).

Better but still a problem.

Now back to a bag of bolts again!

Shop is talking to BMW about possible problems. Anybody got any ideas.

To my, very untechnical mind, something is causing the alt belt to become a problem i.e. it is a symptom not a cause.
 
I'd go with the idea of a siezing alternator too, the belts are good for well beyond the factory replacement interval. I've had 100k from one. If it is the alternator bearings any roughness will show up easily if it's turned by hand with the belt off
 
Have you tried running the engine up with the belt off would be a good place to start to see if the noise was still there.
 
Breaking news

Well BMW dealer has been told to change the alternator by BMW. I will wait with baited breath.

Will post the outcome if anyone is interested.
 
skywalker said:
Have you tried running the engine up with the belt off would be a good place to start to see if the noise was still there.
Click to expand...

Now thats a good IDEA.

You must try it or suggest it to your dealer(they should have tried it without you prompting anyway)

Five stars Skywalker- the force is with you!!!!!!!!!!!!!!!!!!!!!!!!

Nick
 
Noise that could possibly be attributed to alternator

Bike (09,1200) just been well serviced with great care to rocker adjustment etc and now with 20/50 oil and very quiet too! Lovely:)

BUT, from absolutely cold it make a horrible ' clackety clack... knock...clackety clack' type sound which goes away after a very short while. obviosly it is warming up and the oil getting round the engine but it doesnt need to get hot before it dissappears and back to impressively quiet.

Could it be a seizing alternator? could it be anything inside the plastic front engine cover, alternator belt? or behind the main front plate(that corrodes;what''s in there?) and could therein lie the root of the noise?

I am not mechanically minded but I ask all this because is a horrible noise and my perception is that its coming from that area.

Thanks for any help:beerjug:
 
merrick1953 said:
Bike (09,1200) just been well serviced with great care to rocker adjustment etc and now with 20/50 oil and very quiet too! Lovely:)

BUT, from absolutely cold it make a horrible ' clackety clack... knock...clackety clack' type sound which goes away after a very short while. obviosly it is warming up and the oil getting round the engine but it doesnt need to get hot before it dissappears and back to impressively quiet.

Could it be a seizing alternator? could it be anything inside the plastic front engine cover, alternator belt? or behind the main front plate(that corrodes;what''s in there?) and could therein lie the root of the noise?

I am not mechanically minded but I ask all this because is a horrible noise and my perception is that its coming from that area.

Thanks for any help:beerjug:
Click to expand...

My 09 has some time a light mechanical noise when starting from cold, predominantly from the left barrel area (& always after after it got very hot)
The dealer has checked it on several occasions, but they haven't bothered to follow the method in which it's likely to do it...give it a run, Let it get hot on the stand & then leave it overnight.

I'm certain in myself what the noise is..and that the cam chain tensioner...had exactly the same noise, in the same circumstances on my old R1100s
Cured the problem with a new tensioner. so that is what I'm going to install over the winter
 
Kremmen said:
My 09 has some time a light mechanical noise when starting from cold, predominantly from the left barrel area (& always after after it got very hot)
The dealer has checked it on several occasions, but they haven't bothered to follow the method in which it's likely to do it...give it a run, Let it get hot on the stand & then leave it overnight.

I'm certain in myself what the noise is..and that the cam chain tensioner...had exactly the same noise, in the same circumstances on my old R1100s
Cured the problem with a new tensioner. so that is what I'm going to install over the winter
Click to expand...

Thanks so much for your two posts. I will run it up without the alternator belt, on fact spin it by hand first. All after an overnight lay off. Then with alternator possibility eliminated I will assume your past experiences it is likely to be the can chain tensioner. In reflection I think the clackety clack noise is more from the left barrell side so it's looking like you have given me the answer. Your noise does stop shortly after start up I hope??

Thanks
 
So with the front plastic cover off and the alternator belt off the alternator shaft can be spun by hand and it is smooth and quiet and the noise isnt there when running the engine with the belt off!

That points to an alternator generated noise doesnt it? if it makes the noise with the belt on but not when its off?

I will get the mechanic to reassemble it it the morning and see if the noise comes back!

I have read it could be a cam chain tensioner noise but the noise goes on a short while certainly more than a few seconds which i read is all it takes for the tensioner to fill with oil? could I rule out a cam chain tensioner?

Finally the mechanic said a few bits of grit fell out when the plastic cover was taken off and some grit was also embedded in the alternator belt so has anybody heard of this problem? could jet washing push grit in though the small vents? certainly sharp grit could 'clack' if thrown around or on the belt against metal?

Who knows it might all be quiet when I get the bike back tomorrow!

Any help would be appreciated ( apart from dont be such a nutter about noise!!!!)

Cheers:beerjug:
 
merrick1953 said:
So with the front plastic cover off and the alternator belt off the alternator shaft can be spun by hand and it is smooth and quiet and the noise isnt there when running the engine with the belt off!

That points to an alternator generated noise doesnt it? if it makes the noise with the belt on but not when its off?

I will get the mechanic to reassemble it it the morning and see if the noise comes back!

I have read it could be a cam chain tensioner noise but the noise goes on a short while certainly more than a few seconds which i read is all it takes for the tensioner to fill with oil? could I rule out a cam chain tensioner?

Finally the mechanic said a few bits of grit fell out when the plastic cover was taken off and some grit was also embedded in the alternator belt so has anybody heard of this problem? could jet washing push grit in though the small vents? certainly sharp grit could 'clack' if thrown around or on the belt against metal?

Who knows it might all be quiet when I get the bike back tomorrow!

Any help would be appreciated ( apart from dont be such a nutter about noise!!!!)

Cheers:beerjug:
Click to expand...

behind the plastic cover you will find a foam sound deadening block which sits at the bottom, most people ditch these as they retain water and promote corrosion. when I took mine out a load of grit fell out, suggest if its still there you remove it and ensure there is a small gap in the bottom edge of the cover to enable water and grit to fall out
 
What the mechanic is saying is certainly plausible, check everything over & put the belt back on & see if the noise changes, stays the same or hopefully disappears
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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