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1997 R850R Start-up Cam Chain Noise w/Upgraded Tensioner

senseamidmadness said:
This is because I didn't ask for oil recommendations and did NOT want to start an oil thread. That choice has already been made and I'm switching to the correct viscosity. I just wanted to know what was causing my cam chain rattle.
Click to expand...

The most likely cause of your chain rattle is the use of an out-of-spec oil, which means that a discussion of oil specifications is unavoidable.

That said, it is your bike and you can do with it what you wish, whether that meets BMW specifications or not. Your bike; your choice; your risk.
 
In the old days of "side of the road" car dealers, didn't they quite things with really thick oil or sawdust? :eek
OM
 
Omega Man said:
In the old days of "side of the road" car dealers, didn't they quite things with really thick oil or sawdust? :eek
OM
Click to expand...
Belmont Motors on Kingsway in Vancouver was famous for sawdust in transmissions up here in British Columbia in the '70s.
 
Following up for the sake of anybody else who has this issue down the road:

After my oil change to 20w-50, the rattling cam chain noise on startup is gone. My particular bike seems to be overall happier running that viscosity.
 
senseamidmadness said:
Following up for the sake of anybody else who has this issue down the road:

After my oil change to 20w-50, the rattling cam chain noise on startup is gone. My particular bike seems to be overall happier running that viscosity.
Click to expand...

I had an R1150R - almost the same engine except displacement. In 189,000 miles I always used 20W50 SG or SH rated oil. If it was cold enough to need a thinner oil I didn't ride it.

ADDED: I went to the shop and looked up the viscosity specifications. 20W50 is specified for ambient temperatures from 14F (-10C) and higher. 10W40 is specified for ambient temperatures from 4F (-20C) to 68F (20C). 15W40 is specified for ambient temperatures of 5F (-15C) up to 86F (30C).
 
Last edited:
Further follow-up: the noise has returned, but I'm not that concerned about it.

I don't have a garage so my bike has to live outside, and it's been fairly cold lately. The noise is definitely worse when the engine is quite cold, under 50 degrees F, though it still does happen very briefly on hot restarts.
The rattling noise only happens on start-up in all cases, and it goes away as soon as oil pressure builds. Just a blip of throttle (2000 rpm), or less than a second running with the fast-idle lever fully pulled, and it disappears.

I figure it's an old bike and it's just going to make some noises here and there. A tiny amount of cam chain rattle when starting shouldn't snap the guide rail, right?

Maybe I just need to charge my battery. It's been cranking a bit slow on start-up the last couple weeks now that the temperature's really gone down.
 
These generation bikes also had right side throttle plate rattle as they put on the miles. Often got confused with valve noises. Also the clutch can make some funny noises at idle. Try to isolate where the rattle is actually coming from, use a long screwdriver or auto stethoscope to help.

From my R1100 days, the big difference between the old and new tensioner was that the new one didn't bleed down like the old one did. Oil threads tend to head to the basement pretty fast.
 
BC1100S said:
Which begs the question....Who is "Bob" ?
Click to expand...

Well, he is the oil guy, of course. As to why he has any qualifications to call himself the oil guy remains a question.

I did peruse the "Home Page" of the site and found an interesting article by "MolaKule". Cute but not informative as to qualifications. The article is annotated by a good collection of references.

The most telling thing is that sprinkled in the article at several spots were Amsoil ads. I thus suspect some motivation for the claim to fame.
 
cycleman2 said:
These generation bikes also had right side throttle plate rattle as they put on the miles. Often got confused with valve noises. Also the clutch can make some funny noises at idle. Try to isolate where the rattle is actually coming from, use a long screwdriver or auto stethoscope to help.

From my R1100 days, the big difference between the old and new tensioner was that the new one didn't bleed down like the old one did. Oil threads tend to head to the basement pretty fast.
Click to expand...

What kind of "throttle plate rattle" is typical? Which part is it exactly? I ask because I took apart both throttle bodies to thoroughly clean them out a while back. They were nasty inside. Made extra sure that each butterfly was screwed down tight to its shaft, but one of the shafts (I think it was the right side TB) had very slight axial play.

As for valvetrain noise, I noticed an uptick in that after I did a very needed valve adjustment about 1500 miles ago. "Tappy valves are happy valves" and all that. Sounds like sewing-machine noise all the time while running, and not CLACK-CLACK-CLACK-CLACK-CLACK on startup.

The clutch doesn't seem to make any noises, as cold starts have the same clacking whether I start with the clutch pulled in or not. I sometimes have to start it up with the clutch in as normal procedure due to the typical slightly-lazy neutral light.
 
senseamidmadness said:
What kind of "throttle plate rattle" is typical? Which part is it exactly? I ask because I took apart both throttle bodies to thoroughly clean them out a while back. They were nasty inside. Made extra sure that each butterfly was screwed down tight to its shaft, but one of the shafts (I think it was the right side TB) had very slight axial play.

As for valvetrain noise, I noticed an uptick in that after I did a very needed valve adjustment about 1500 miles ago. "Tappy valves are happy valves" and all that. Sounds like sewing-machine noise all the time while running, and not CLACK-CLACK-CLACK-CLACK-CLACK on startup.

The clutch doesn't seem to make any noises, as cold starts have the same clacking whether I start with the clutch pulled in or not. I sometimes have to start it up with the clutch in as normal procedure due to the typical slightly-lazy neutral light.
Click to expand...

The part that wears is the throttle plate shaft. The bores that this shaft goes through also sometimes wear but the real wear is the shaft itself. Then at idle the induction pulses cause the shaft to vibrate in the bores and it ticks.
 
Ah, I have heard of that before and saw a picture or two a few months back. I did make sure to check that when I cleaned them, and didn't notice any abnormal amount of wear. The shaft looked perfectly round in both the spots it fits tightly into the throttle body.

Is it possible I got a faulty tensioner piston? The MOA member who sold it to me through the Marketplace said it had been sitting in the package for years; perhaps the ball valve is leaky?

Edit: I should mention my original tensioner with the 17mm head seemed to work just fine, and I did not notice any start-up clacking until *after* I made the change to the new tensioner.
 
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