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

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?

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

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?