The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: erod1 on October 20, 2012, 05:56:25 PM
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So I removed the front engine cover to see and or hear what sounds like the timing chain rattling . I turned the bike on. It sounds to me like the noise is coming from the alternator . Could that be possible ?
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It's a 'pre-owned' vehicle, anything is possible !
There are three allen head bolts that hold the stator on, one bolt that holds the rotor on, check those for security .
Only other thing after that, is the two brushes that contact the rotor slip rings .
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I Checked the three bolts, all tight. It seems to be coming from inside. Who knows maybe it is the chain.
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does the noise go away when you rev the motor past 2000 rpm?
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Yes. It is only at idle.
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I'm watching this thread closely. I also have this mysterious noise at idle...only. I can only guess it's coming from the timing chain, but with so little miles (realtively speaking), steady timing marks and no signs of debris in the oil pan it's hard for me to break open the front door of a great running bike with a recent fresh top-end. I've also noticed other R65's in the neighborhood with the same noise. Is it something inherant?
During my restoration tear-down I thought I solved this issue and uncovered a hidden problem. Even communicated with Oak which he agreed. I discovered my pushrods with score marks during the tear-down. After measuring the mark's positions it was determined they were caused by contact with the ends of the pushrod tubes near the head. Oak instructed me to carefully grind the ends smooth which I did. But after reassembly - the noise again appeared. There was obvious contact with the pushrods and tube ends as you can see by the attached photos, but no possible adjustment in the towers to make up such a difference. The last photo is where Oak and I decided to do the trimming with rotary tool.
The noise is only at idle and with a warm engine. During start-up when cold it is dead silent except for the expected valve noise.
So, my question to you guys...have any of you noticed scoring on your pushrods? See attached photos for marks and machining. The large 2nd photo shows the contact point with the pushrod. Pushrods were straight during inspection.
1981 R65
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I had the cylinder heads off going on 15 years ago, I noticed polished marks on the pushrods .
I found the cylinder head gasket holes for the push rods, were too small and the pushrods contacted it, it was quite obvious by the looks of the gasket .
I never looked at the inside of the pushrod tubes to see if there was contact there .
Ed Rod, I don't know what to tell you now about you're noise .
Guess it will be your call on where to go with it .
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Bob - Ed,
If we are experiencing the same noise I don't know what else it could be other than the timing chain. The pushrod tube trimming didn't stop the noise. I won't know what the cause is until I bite the bullet and get into the timing chest. Something I'm not in a hurry to do. The noise I hear with my bike shadows the symptoms Ed is describing. Very strange. And annoying.
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i guess the part that gets me, i know im doing a timing chain job this winter, mine is a ticking sound in the front till about 2000rpm but my bike has 42,000 miles on it
but also on a side note, i have ticking noise coming from the right cylinder at the majority of speeds, there are some RPMs when its quiet but for the most part, its the loudest thing you hear, it does increase with RPM. I have very recently adjusted the valves and still no relief, when i do a top end job, ill worry about it if it makes the same sound after