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Rod Knock?

Posted: Sat Jun 02, 2007 4:27 pm
by NoRRmad
I took my '02 R1150R in for service about 10,000 miles ago and after the (24,000-mile) service and maintenance, the tech told me that he thought I had "rod knock." Apparently at 4000 RPM he could hear a distinct sound. We ran it up to 4K and he looked at me significantly as though I should hear it. (I really didn't hear anything out of the ordinary, but I recognize that a tech will have a better-trained "ear" than I do.) He thought that I might have a bad small-end bearing on the left cylinder con-rod. This was my first service after my warranty ran out. I told him I'd keep an eye (or ear) on it. 6,000 miles later, I took it to another shop for the 6K-interval checkup (I was on the road,) and told the tech that the motor sounded "funny at about 4K RPM," and asked him to have a listen, but he didn't note anything.

I ride with earplugs and the stock exhaust and frankly I can just barely hear the engine when I'm cruising. I'm not a speed demon; I rarely exceed the limit by more than 10 MPH, and I'd rather run local (45 MPH) roads than scream down the Interstate. I ride solo with about 50 Lbs. of touring gear. Seems to me that I baby my bike.

I have 34,000 miles on the bike, now, and recently took it back for service before a trip (jumping the gun a bit on the 36,000-mile service, but I wanted to be safe.) I sat down with the service manager and asked him about the repair for "rod knock." He agreed that it could be the small-end bearing -- or the wrist-pin, or the piston bearing, or all three. Or the big-end bearing, which might require a new crankshaft. All apparently very expensive to repair. His suggestion was to sell the bike and get a new one. I told him that the new BMW's dont really interest me; even the 1150 seems like overkill for my style of touring and the F800 is tall and a bit Ricky Racer for my taste. I'd probably change brands if I couldn't keep my RR.

I asked how this could happen, and he suggested running with the oil low, which I'm pretty careful about, or water in the oil, which I don't know how to check, (but I do replace it every 6K miles,) or overheating, which is possible; often I find myself in stop-and-go traffic, and under some circumstances you can't shut down every ten feet. Once at a tunnel exit waiting on an uphill ramp I ran the engine at a crawl for a good fifteen minutes, and I could feel the heat through my Roadcrafter pants (over jeans.) Finally I was able to pull over and shut down for a few minutes, but the catalytic converter was obviously pretty hot.

I guess my questions are these:

Is this reasonable? An '02 RR with 24,000 miles developing rod knock?

Is there anywhere a sound file to tell me what rod knock sounds like so I can know what to listen for?

Is this a repair I could do by myself? I'm not tool-shy, but I don't have a shop or a garage.

Thanks for your advice. :oops:

Posted: Sat Jun 02, 2007 4:40 pm
by iowabeakster
about 10,000 miles ago and.....This was my first service after my warranty ran out.....I told him I'd keep an eye (or ear) on it. 6,000 miles later, I took it to another shop for the 6K-interval checkup (I was on the road,) and told the tech that the motor sounded "funny at about 4K RPM," and asked him to have a listen, but he didn't note anything.....

I sat down with the service manager and asked him about the repair for "rod knock." He agreed that it could be the small-end bearing -- or the wrist-pin, or the piston bearing, or all three. Or the big-end bearing, which might require a new crankshaft.... His suggestion was to sell the bike and get a new one.
I'd give it another 10K and make your decision then.

Ask around and find a good independent mechanic. Have another person check it out. Preferably one who doesn't sell new motorcycles.

Posted: Sat Jun 02, 2007 5:53 pm
by Rootin55
I just got my 04 Rt from the shop this past Thursday. It was there almost 2 months. I have just over 14K on her and I want to say I started hearing a knock at around 11K miles. When I had my 12K serice done (@13K) the mechanic told me I had a bad rod bearing. I heard a noise starting at 4K rpms as you describe and all the way up from there. At this point, I decided to run an oil analysis. Babbit bearings (others too) will show excessive bearing wear with high lead & copper readings. I checked it again with a short run of 1200 miles and those 2 elements were higher. Long story short, BMW of North Houston went to bat for me and I got a short block (new) installed. This is just about everything except the pistons, rings & jugs. Here is the oil analysis that was run. I never had the oil below 1/4 of the site glass and other than stop & go traffic always ran 5 bars (temp reading). I can only assume the oil got thick (see report) due to extra friction caused by the bad bearing. I had been running Mobil 1 20/50 V-Twin, which carries an API SG rating. Hope this helps.

[img][img]http://i3.photobucket.com/albums/y77/Ro ... 09_001.jpg[/img][/img]

Posted: Sat Jun 02, 2007 10:30 pm
by RBrider
Ken

The oil analysis was a great idea. The diesel shops do it all the time.

NoRRmad, sounds like it would be a good next move for you, as well. If nothing else, it might give you piece of mind.

RB

Posted: Sat Jun 02, 2007 11:16 pm
by MIXR
Make sure it's not just a cam chain anti-slap piston and cylinder. Your '02 will have the early (original) parts. Look for the 17 mm head on the cylinder top of the cam chain 'tensioner'. (It's not really a tensioner - Just stops the cam chain from 'flapping'). The new parts have a 15 mm head.

It may be nothing to worry about. If you have a long bladed screwdriver (really long), or even a thin piece of steel tube (not rod), then you can place one end on the possible noise sources and listen at the other end. In this case, one end on the cam chain cylinder, and the other end in your ear. Be careful!

Run the engine up to the 'noise-zone', and have a listen. If it's not that, try and pick up where else the noise might be coming from by moving the tube or screwdriver around the engine bearing points. Naturally, we are still on the ouside of the engine here! Don't overheat the engine.

The tube allows the noises to be amplified. So does the plastic end of a screwdriver. If you're a Doctor, a stethoscope would be even better.

Here's the link to my cam chain tensioner replacement, just in case.
http://www.r1150r.org/board/viewtopic.p ... 5493f2a044

Posted: Mon Jun 04, 2007 5:27 am
by NoRRmad
Thanks, guys. Some good suggestions here. I know the sound of chain slap, and I hear some at startup or when cutting the throttle suddenly. My problem I guess is that I dont really hear anything that sounds bad; it's just the mechanic that hears it.

Rootin55, that's a good idea; if there were any bearing wear, it'd probably show up in the oil. How does one go about getting an oil sample tested? Can the local Jiffy-Lube set that up for me? :oops: (I'm really distressed that a Roadster actually did have rod knock at such low milage!)

Posted: Mon Jun 04, 2007 6:31 pm
by RBrider
NORRmad

If you can't get help from anyone else, check with one of the big factory diesel shops like Caterpillar or Cummins Diesel. They'll be able to give you the name of a lab.

Or call an oil distributor.

Any of the above will be in the yellow pages.

Good luck
RB

Posted: Mon Jun 04, 2007 10:45 pm
by Byrdguy
The throttle bodies on these bikes clatter a good bit. Give them a good listen with the pipe or long screwdriver. Most noticible when the throttle is just barely cracked. I think the noise could be mistaken for con rod knock at times. There are a lot of parts whirring around inside and there is going to be some noise. From everything I've read and heard, these engines are pretty solid and reliable. Try to get several opinions from people in the know before taking any drastic measures. Keep us posted.

Posted: Tue Jun 05, 2007 10:57 am
by ProductUser
The sound could be coming from an enlarged rocker end gap clearance.

Just a thought.

ProductUser