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Clatter under maintenance Throttle


TripleThreat

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TripleThreat

Recently purchased a 2004 R1150RT with 52,000 miles on it. It's in great shape and has good maintenance records. I noticed a bit of clatter under maintenance throttle above about 3200 RPMs. Figured I might have some valves out of adjustment...

 

Yesterday I completed a valve adjustment, oil/filter change, Transmission and Final Drive Gear Lube change. Valves were out of adjustment, but not terribly so... Spent quite a bit of time tweaking the adjustment to ensure that everything was equal.

 

Today, I rode about 100 miles to a local BMW club meeting and back home, hoping that the clatter under maintenance throttle would have disappeared. It is not gone...

 

Looking for ideas about where this might be originating. It doesn't exist under acceleration or deceleration, just under maintenance throttle. The bike runs great, just can't figure out where this clatter is coming from.

 

Jeff

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Baseline questions:

 

Have you ruled out worn throttle body shafts yet?

 

Have you checked/adjusted rocker arm end-play?

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Morning Jeff

 

Can you explain the noise in a little more detail? Is the "clatter" just a general noise or specific type noise.

 

Can you tell if the noise is in sync with each revolution or every other revolution or ?????? (Once per Rev or faster/slower?)

 

Things like R/H throttle shaft (or bushing) rattling occur every other revolution (1/2 engine speed) & usually show up at curb idle or at very very light throttle (just slightly above idle).

 

Same 1/2 engine speed with a valve as it only opens every other piston stroke.

 

In the no-load 3000 RPM range the usual cause of internal engine noise is timing chain noises (L/R or front) with some chain noise normal, & some indicating not enough tension or a chain rattling on the guides.

 

You also have to keep in mind that the BMW boxer engine is exposed (no sound deadening hood over it), & you sit right over it, so normal engine noise sounds louder & sounds courser.

 

Does the noise decrease if you lower the windshield all the way down? In a lot of cases normal engine noise bounces off the windshield & sounds louder.

 

Does the noise change or get louder from cold engine, to hot engine, to hot engine after a long ride?

 

Diagnosing an engine internal noise is difficult enough when leaning over the engine & almost impossible over the internet.

 

What I have found that works pretty good for isolating BMW engine noises (not 100% but pretty good) is to buy a cheap mechanics stethoscope, then remove the stinger & remove the diaphragm, then use the open hose to listen around on the engine (just close, not ON the engine). Using this you can usually isolate the AREA that the noise is coming from. Once you have the area defined , & know the speed of the noise (once per rev, once every other rev, twice per rev, etc), you can ask us here what the noise might be coming from inside the engine.

 

One last thought-- If you usually ride with ear plugs, then one day ride without them in, your engine will sound like a metal trash-can half full of rocks rolling down a hill.

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TripleThreat

D.R.

 

Thanks for your reply. I will attempt to isolate the sound via stethoscope as you describe. I do normally ride with high quality custom molded earplug speakers that connect to my SENA SMH10 Bluetooth Module and I listen to music from my Zumo 660 while riding. With them in, and the music on, it's a peaceful and smooth ride.

 

With them in and the music off, I can hear the clatter fairly well. With them out, I'm not sure the whole thing is going to hold together...

 

I haven't tried a change in windshield height while comparing the noise level, but will try that on my next ride to determine if there is any change.

 

At idle, the bike makes very little engine noise at all, in fact, I have to get fairly close to each head to be able to hear valve noise. It's there, just not abnormally loud. I adjusted the valves on Saturday and was pretty meticulous about ensuring that the adjustment was accurate and even (in terms of tension on the feeler gauges - used 4 feeler gauges at once), not only between valve on the same head, but even between all 8 valves (of course utilizing the appropriate gap for intake vs. exhaust).

 

 

My guess is that it might be timing chain related. I may also try to see if I can get a decent audio recording of it utilizing my VIO POV Camera setup.

 

Jeff

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clip--

 

At idle, the bike makes very little engine noise at all, in fact, I have to get fairly close to each head to be able to hear valve noise. It's there, just not abnormally loud. I adjusted the valves on Saturday and was pretty meticulous about ensuring that the adjustment was accurate and even (in terms of tension on the feeler gauges - used 4 feeler gauges at once), not only between valve on the same head, but even between all 8 valves (of course utilizing the appropriate gap for intake vs. exhaust).

 

 

Evening Jeff

 

Please explain this using 8 feeler gauges at once? You can ONLY adjust one side at time then need to turn the crankshaft 360° to adjust the other side. I'm not clear on how you used feeler gauges on the non-adjustment side as there is no clearance on most valves on the TDC (non-compression) side.

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TripleThreat

D.R.

 

Re-read that... I said that I used 4 feeler gauges at once and tried to balance the friction on each feeler gauge at the appropriate gap at all valves.

 

I used Two .30 mm (exhaust) and two .15 mm (intake). I did one side at a time, setting TDC on each side by rotating the crankshaft using the 16 mm bolt on the front of the crank pulley behind the alternator belt cover on the front of the motor and centering the OT in the timing hole. I made sure that the valves were free on each side before I adjusted (TDC on that cylinder).

 

What I failed to describe accurately in my previous post was that by using these 4 feeler gauges I tired to balance the friction on each gauge on one head (intake and exhaust at appropriate gap), then tried to adjust the valves on the opposite cylinder (when at TDC on that side) so that the same amount of friction existed on the feeler gauges.

 

My description was vague and confusing... I do know what I am doing, I just can't seem to articulate it clearly...

 

Jeff

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Evening Jeff

 

OK, the "even between 8 valves" sounded like you did both sides at once. (just trying to clarify things so we don't miss anything simple)

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TripleThreat

D.R.

 

I rode the bike to work today, without earplugs. Played with the height of the windshield, but that didn't really result in a significant reduction in the noise.

 

I paid a bit more attention throughout the day as I rode several times between going to work, meetings, a hair cut, a national junior honor society induction for my youngest daughter, and then home again.

 

The noise seems to be more centrally located near the front of the motor, rather than on either jug... Also, the noise is present, but faint below 3000 RPMs. It is also present, although a bit muted under acceleration. It becomes very noticeable just as bike speed catches up to throttle position and then quiets down. At idle, the bike seems fairly quiet. Under steady throttle in neutral, it is also fairly quiet. It becomes very noisy if I rapidly accelerate in neutral, just as the engine catches up to the top of the throttle induced rev. In other words, just as acceleration tops out at a given throttle position.

 

I also noticed that as the engine reaches full operating temperature, the noise is more prevalent at low RPM maneuvering, such as slow corners in first or second gear in a city traffic situation.

 

I have not placed a stethoscope on the motor yet, but that will be my next step. It is a deeper tone noise, not high pitched.

 

I'm also in the middle of rebuilding the motor in my Land Rover Discovery II, so there hasn't been a lot of spare time...

 

Thoughts?

 

Jeff

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Evening Jeff

 

Difficulty to say for sure without some sort of specific area that the noise is coming from. (even then engine noise tends to telegraph)

 

Your noise has the earmarks of front accessory shaft chain noise. That is a VERY DIFFICULT area on the BMW boxer to define or pin down noise location or cause.

 

I have personally worked on some BMW boxers that had front chain area noise & never really found the problem with a specific part or parts. Replaced chain, tensioner & guides & noise went away but no real confirmation of what part or parts were the root.

 

I guess what I'm saying is: if you can pin the noise down to the front accessory chain area you can take it all apart & might not find a smoking gun in there.

 

The good news is, even though noisy, the front chain area seldom if ever seems to effect engine durability or cause any failure problems, so the engine can probably live a long & happy life with front chain area noise. (as long as the chain isn't contacting the case or the guides are not worn out or broken.

 

But, lets not get the cart ahead of the horse here so try to define the area the noise is coming from before making a decision on what to do.

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  • 3 months later...
TripleThreat

After a bit of continued riding, with no ill effects on performance, I circled back around to trying to find the source of the clatter. I thought perhaps that I had found the culprit in worn throttle body shaft bushings, but after further investigation there it appears to be not so simple as throttle body shaft bushings... I pulled off the bodywork this morning and did a little investigating. I can put my finger on the throttle cable pulley on either throttle body and the noise does not change.

 

Here is a link to a video from each side where you can hear the knocking sound.

 

Left Side

 

Right Side

 

It also sounds like I may have some type of vacuum leak on the right side somewhere, so I'll have to do a bit of digging on that.

 

The bike has 54,200 miles on it. The Cam Chain tensioners were replaced with the new style at 43,250 miles, so I am guessing that is not the problem.

 

I am beginning to wonder now if I might possibly have a bad pushrod. I know that the pushrod design involves a round end that is pressed into each end of the pushrod and that they can come loose and cause considerable noise.

 

Any other ideas from listening to these video clips?

 

Jeff

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Afternoon Jeff

 

Throttle shaft/bushing issues are usually only audible at or close to idle. Once the throttle plates are opened then the cable tension & less throttle plate area exposed all but eliminate throttle plate rattle.

 

If you had an early 1100 bike then a collapsed pushrod would definitely be a place to look but I haven't ever seen a late 1150 with the newer push rods collapse one. In any case, if a push rod collapse issue, then you would have excessive, & easy to find, valve clearance on that valve. (I presume you have checked the valve lash?)

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TripleThreat

D.R.

 

Yes, Valve adjustment is spot on as is rocker arm end play... When watching the videos back, the noise really sounds like it's coming from deeper than valve train... Maybe lower in the case than the head.

 

Jeff

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TripleThreat

D.R.

 

I wasn't thinking that the push rod had collapsed... Thinking that perhaps an end came loose...

 

Fast forward to 4 min. in this video (excuse the foul language - Not my video)

 

 

Thinking I might pull the rocker assembly to check for that. Seems like pulling the rocker assembly is not that big of a task and that would at least eliminate that as a possible source, or confirm it...

 

Jeff

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Morning Jeff

 

If the end did come loose (very very unlikely) then it would be trapped by the valve lash on that valve so shouldn't make any more noise than the normal valve lash clearance.

 

I don't have much (usable) sound on the laptop I have with me this weekend so really can't tell you much from your sound clip.

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TripleThreat

D.R.

 

Makes sense! Perhaps I'll just run it since it seems to not be having any impact on performance...

 

Jeff

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D.R.

 

Makes sense! Perhaps I'll just run it since it seems to not be having any impact on performance...

 

Evening Jeff

 

That will probably work, if the noise doesn't get worse then probably not an imminent problem.

 

In any case if you do run it for a while you might consider sending in an oil sample to BlackStone Labs after 500-100 more miles. They are pretty darn good at telling you what is in the oil & if engine problems are in your future.

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  • 1 month later...

Well, I rode the bike to Barber for Vintage Motorcycle Days. It performed fine, but clattered any time the engine was not under heavy load or under significant downshifting deceleration.

 

At idle there is no noticeable clatter, but just off idle with no load the clatter is significant. In every gear, under hard acceleration the clatter goes away until the acceleration forces decrease as the bike catches up... Once there is no longer heavy load, the clatter returns.

 

Likewise, if aggressive downshifting is used to decelerate the bike, the clatter goes away until the deceleration forces decrease to the point where the bike is almost returning to a coasting state.

 

The bike got 40 - 42 MPG while traveling fully loaded, 2-up, at sustained speeds on the way down of 70-75 MPH and 75-80 MPH on the way home.

 

It is loud enough to be heard at highway speeds, even with custom molded earplug speakers in unless I turn the music volume up fairly high.

 

It's really annoying, and it is the only thing keeping me from completely loving this bike... Looks like a potential winter teardown to diagnose and repair...

 

Jeff

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Know how you feel TT. Have spent the last 3 months trying to track down miss in the engine (not surging). Spark plugs, wires, coil, double checked tb sinc and valve adjust. It only happens in closed loop. Yank on the throttle and I can lift the front tire off the pavement (never could do that before), but during casual accel or cruising along it feels like one cylinder kicks in and out continuously...drives me crazy. I'm taking a break from it before I apply a blow torch. Next I'll probably check out the 02 sensor. It has not been a fun year with this bike after already replacing the input shaft after my splines shredded after only 32000 miles. Pulling the tranny on theses bike is not fun.

Good luck to you.

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You might have tried this already but try disabling each cylinder one at time and see if the sound changes. I think the nature of the noise is different between the left and the right jugs. The right sounds a bit more metallic. To me the left sounds like a rod bearing or even piston slap. Like I said, pull a plug wire and see how it sounds. Either way, you could probably ride it like that but don't expect the bike to cure itself or the noise go away. It's not a good noise.

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