1150 RT dreaded death rattle?
Bike: '04 1150 RT with 80,000 miles. Well maintained.
I thought an out-of-adjustment tappet was the cause of the increasingly loud "tapping" noise. So I reset 'em. The noise continued, especially on the right side. I'm satisfied that I've eliminated valve adjustment as the cause of the tapping noise. But, what?
Here's a credible clue: With oil topped off, engine warm and idling (and 'tapping'), while straddling the bike, standing flat footed on the ground, if I lean it to the right, assuming I'm allowing oil to flow downward to the right cylinder, the clicking/tapping goes away.
I have a hunch someone out there knows exactly the cause. My fingers are crossed that it's not a faulty oil pump....
Thanks for your input!
Last edited by Axel39; 04-23-2013 at 04:28 AM.
Reason: forgot to mention model in original
Could it be a bad cam chain tensioner??
Axel, the "death rattle" as I understand it occurs on the left cylinder immediately on starting the engine. The primary cause is due to the design of the cam chain tensioner on that cylinder. It's more annoying than anything and can be easily fixed by replacing the cam chain tensioner. Here is a link to a good explanation on how to replace it. "advwisdom.hogranch.com/Wisdom/cam.pdf"
I have a 2004 R1150GS with 12K and noticed a mild rattle at startup. After reading several posts on the internet pertaining to this issue I replaced the left side cam chain tensioner(about $85 from my local BMW dealer). Apparently the left one has a history of having a weak spring and after time causes what many describe as " the death rattle". The new tensioner from BMW is hydraulic and eliminates the spring. The new tensioners have a 15mm head, the older "spring" versions have a 17mm one. It took me about an hour to change it out eliminating the annoying rattle at start up! The left side is a pain to get to but it can be done by sliding the left throttle body backward into the air box to gain access. The right one is located on the under side of the cylinder and is easy to access on my GS but I find no need to change it out at this time. There are a lot of videos on youtube showing the whole procedure from start to finish if you need a go-by.
Good luck! hoped this helps.
the problem with the original CCT is not that it contained a weakening spring, but that the tube the spring sits within had a design that allowed oil to drain out of it as the engine cooled. with teh oil out, it did not retain full tension on teh cam chain. once it pressurized with new oil (about 10 seconds after startup), the rattle would go away.
the only danger with the rattle would be a gradual wearing of the cam chain guard, which could eventually break (typically, good for over a hundred thousand miles). that, and the teasing you'd be subjected to from your Harley friends, as they might even hear that rattle over the sounds of their open-pipe "life-saving" exhausts.
but that is not an issue on the right side.
tilting the bike to the right does not give increased oil flow to that side, it only changes the dynamics of the sound waves reaching your ears.
i suspect that a faulty oil pump would cause more noise than just the sound of clattery valves.
have you asked your dealer to listen to it?
You have adjusted your valves, but have you checked the end play on the rocker shafts? Mine were at the upper level of the adjustment range and a little noisy. I adjusted to the lower level of the range and it made quite a difference in the sound, much quieter.
Of course, as others have said, changing the left side cam chain tensioner if you still have the early 17mm one will eliminate the clatter at start-up.
B'fish and Festes are both right on; here's one more consideration:
When adjusting your tappets, did you have TWO feelers inserted at the same time, one in the upper, and one in the lower? This is to eliminate the small "rocking" effect along the vertical axis of the shaft. And do have confidence that the feelers are not worn or just inaccurate?
Excellent!! 'Gotta admit, didn't even think of end play in the shafts. I've checked clearances within the bushings, but not end play. Thanks, Festes. I'll be heading out to the shop asap to check end play.
Originally Posted by festes
Good information on the cam chain noise. Thanks. But, I wish you were right about the sound waves reaching my ears. I didn't make clear that the rattle did not go away immediately after leaning the bike to the right. It gradually went away several seconds after the lean. It was clearly audible to me after I initially made the lean. Sorry for the confusion.
Originally Posted by bikerfish1100
If you are right about the oil flow to the right when leaning in that direction, I'm wondering if Festes thoughts are confirmed possibly due to gravity, i.e., maybe the end play is affected by the shifting. ???
Thanks to all who weighed in. I learned a lot.
Originally Posted by MCrenshaw
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