Rattle on R1100 engine
 

Hi all,
Have a rattle coming from the front of the engine (R1100) when I pull away in first or on heavy load going up a hill.
any ideas?

What kind of mileage? Might be a big end or main journal about to expire.
Does it get worse with increasing oil temperature?

Hope you have a good BMW workshop nearby :(

rattle on R1100 engine
 

No, does'nt get worse with increased oil temp. Could it have something to do with the tensioners on the cam belt

The cams are chain driven. There is a widespread problem on high mileage R 1100 engines with the cam chain tensioners. They are hydraulic and the chain tension decreases when the engine is switched off for a while. This results in the engine being very noisy on start up but the noise disapperars after a few revolutions with the oil pressure building up. This problem does not seem to create any further trouble.

Noise under load also does not point at a valve train problem as this would be determined by rpm mostly and to little extent by oil temperature (viscosity) in hydraulically operated items like the timing chain tensioner. Unusual valve train noise is most easily recognized at idling speed when it's not masked by increasing normal engine noise & wind & tire noise.

Main reason for noise under load is worn big end or main journals. The sound is a very hard, loud knock like a hammer hitting hardwood. Small ends theoretically but they tend to seize rather than wear out. Extremely low oil pressure will also cause noise and will cause damage to said journals almost immediately.

Another possibility is uncontrolled combustion (knocking) caused by carbon deposits in the cylinder head and on valves or extremely bad fuel quality. The BMW's motor management should counteract this but I don't know to what extent it does.

Get a mechanic to listen to the engine.
Where are you?

Rattle on R1100 engine
 

Thanks for that, still in the dark though! The rattle is like a ticking sound, not unlike a chain whipping when loose.This has been happening for the last 2 weeks with no change for the worse. Will give the bike an oil change this weekend and give it a good once over. Unfortunately I live in the south of Ireland where good mechanics are hard to find and the only people with the tooling are the main dealers. Paudie:scooter:

Valves
 

How loud the noise really is?

Note that horizontally mounted boxer or V-engines (Guzzi or BMW or Honda Goldwing) with uncovered stickly out cylinders have valve noises better noticable. You don't notice many normal sounds on bikes where the cylinders are hidden under the tank and covered with an air-box, sounds that are actually relatively normal on very hard low-rpm acceleration etc., nothling screamingly loud but nothing like completely silent going eighter.

But if it's really loud:

Check and adjust valve clearances and rocker end play, they are probably off the spec. I'm 80% sure it's the case on your bike.

OR:

I had similar problem in Iran running below-80 octan petrol, it did bad valve noise under load (hard acceleration or a steep climb) plus it was leaded petrol that built a slight layer of carbon on the pistons = a very minor pinking sound was also noticable, but it didn't gave me any problems and the bike didn't miss a beat per 17,000+km w/o any maitenance or service at all (do not try that on any jap bike where everything floats in the same oil) in very harsh conditions. It dissapeared after returning to Europe where higher ocan was available. Have you recently been running bad quality petrol mayhaps?

Sorry to say but that reply is utter rubbish in a number of points:

Bad fuel quality such as a low octane level does not cause any valve noise at all. It causes pre-ignition which in the long run can do damage to the piston, gudgeon pin, small and big end journal / bearings of the conrod and crankshaft journals / bearings. No make of engine is immune to severe damage caused by preignition, not even a BMW.

The addition of tetraethyl lead increases the octane level of the fuel and helps to prevent pre ignition which can be heard as knocking or pinging noise. The lead additives help to reduce valve seat corrosion. This is no issue on more recent engines as developments done since the 1970s were designed to run on lead free fuels and employ hardened valve seats.

Leaded petrol does not build up carbon layers on pistons.

Margus:
In response to your ongoing pink BMW goggles biased flaming of japanese bikes I can assure you that many japanese bikes do many kilometres while only receiving rudimental or no service at all while everything floats in the same oil. I have seen and worked on many of them.

Not that your or my comment help the topic :)

Sorry mate, maybe search some info about poor quality fuel before restarting all the BMW-bash club agenda again.

I agree on pinking and I did used octan booster that made only a small improvement, 1100GS eated surprisingly well a low octane fuel. Valve noise actually ocurred later (explanation above), not instantly.

Bad quality fuel, which I actually ment, does build up a carbon layer. Poor quality fuel just doesn't 'fully' burn, leaving deposits.

Deposits from unburned or partially burnt fuel collect in the boundary layer especially in isolated pockets causing at times significant build-up of carbon deposits.

Since the combustion volume is reduced due the carbon build up then the compression generated by piston is higher - valves and their timing are usually specced for the 'stock' compression ratio, but if it exceeds it, then I reckon it'll start to make some additional noise due very simple mehanical reasons: valves, especially their springs aren't configured for taking higher than native "blast" forces.

Sparkplugs were coloured red, just as the leaded fuel was coloured with strange slight-red tone in Iran. So this is where the deposits idea came to me first.

And the proof for this was as sayed before it didn't occured instantly and also when I returned to Europe, it took quite some time of riding on quality 95/98 octan fuel when the hard acceleration noise finally dissaperared. My guess is it was when the deposits were "cleaned" by better quality fuel that had better cleaning/lubrication characteristics.

If it were some other reason, i.e. off the spec valve clearance or rocker end, then the noise should have been continuing despite running on better quality fuel.

Sorry mate, I use no coloured goggles when riding, a clear visor does for me where everyting is visible as it is in the reality, no myths generated... I've been working on japanese bikes and have some experience too. Many of them are made out of cheese in fact, not all but certanly lot of them with serious potential weak spots. You can simply erase the myth from your head that jap bikes are superior to everything else on the planet Earth. In case you're now looking for excuse for another BMW bash-session then: I'm not saying that BMWs are somehow, btw.

Cheers, Margus

Dear Margus,

please note:
I did not say that your BMW is a bad bike. I do have a 1100GS myself as you can see on my website. Besides a number of other bikes. I also used to have Funduros, 650GS's & Dakars.

You say:
"it didn't gave me any problems and the bike didn't miss a beat per 17,000+km w/o any maitenance or service at all (do not try that on any jap bike where everything floats in the same oil)"

You say about japanese motorcycles: "Many of them are made out of cheese in fact, not all but certanly lot of them with serious potential weak spots."

I do not have a personal feud with BMW or BMW owners and I never had one. I gave my oppinion on various occasions mostly about F650's which I don't use any more for good reasons. I have proof in my records for every problem I criticised the F650's for.
Now you come and tell me that most japanese bikes are crap and made of cheese?

Sorry, dude, you should stick to FACTS you can PROVE and not just throw your toys out of the cot as soon as someone tells you that you talk rubbish.

Almost there, but still you didn't get the point. That was: there is no ideal bike!

I'm very liberal in these ways. And you seem not to have any sense of humor? Starting to take it very personally like mr. Mollydog, i.e. japs made out of "cheese"? Say cheese then, and have a laugh :)

My only problem is that there are still people like you continue to bash (whether hidden or exposed way) everything that's not having "made in japan" marking on it. Creating a mythical image like only there the best bikes are made.

It's been discussed here many times that every bike has it's weak spots, by design or by the same line production variation, and you only have to learn to live with them. No make no country no continent made bikes are immune to it *. But still many people come to say: "hey, jap bikes never had that kind of faults and that amounts of them. Those italians are complete crap, germans are nazi tanks, Triumphs just suck" etc etc. While I have certan experiences, facts in fact, that jap bikes can be even worse.

But what does it prove? Read sentence marked with * again.

Got the point?

There's nothing personal here I must remind you. Just trying to give my little piece to liberate motorcycling world that still lives in the dark age of ongoing myths.

I am beginning to think we need higher sided cots in here :)

Uh Oh and Magus's holy cow BMW also goes down the drain as they convert to the dark side and let everything float in the same oil!

It started with the Funduro which was still excusable, that little Noale assembled bastard with the Rotax engine that pretended to be a real BMW. Even when the assembly line was moved to Berlin it still remained the unholy unit block spaghetti cooker with the Almdudler engine.
Proven by the brand new G650 models which again Almdudel off the Aprilia asseembly lines in Noale.

Then we had the K1200 II that sacrificed the virtues of the holy telescopic forks and their heir Telelever and came along with a 1970's Norman Hossack front end and an inline four looking like a... like a...
like a...
Japanese cheese engine!
A transversally mounted inline four! Shocking!
With everything floating in the same oil!

More shocking news for the BMW traditionalists surfaced when BMW introduced the new 800cc twins. The times are getting hard for air cooled flat twins. The BMW engineers have realized that the lightest and quietest twin is inline and water cooled with overhead camshafts. Quite different to the traditional "Boxer"
While the parallel twin was the preferred British way to build motorcycle engines for many years it was later copied and improved by the Japanese.
They turned the Twin into OHC (CB 450 and XS650) and even DOHC (Z750) air cooled constructions and brought them to the water cooled perfection of a TDM - as the Germanns did with the MZ1000S.
Note that the BMW engineers did not reverse the 1963 decision of the Triumph engineers to move the Bonneville to a unit construction.

The new 800 will sign the death sentence of the Boxer.

And then even Margus's gearbox will have to float in the same oil.

Rattle fixed
 

Paudie,
I hope your rattle is fixed now!

Dave