Loud tapping after warmed up.

[Dave334478]

1997 R1100R 55k mi.

 

This is basically me documenting my troubleshooting not neccesarily asking a question but if you have advice or experiences to add please do.

The bike runs great. After riding for a few miles I hear a loud tapping at idle that decreases as the rpm's increase. It sound like excessive valve clearance. If I let the bike sit and cool for 5 minutes the sound is gone when I start it back up.

 

First, I readjusted the valves using 4 feeler gauges at once as shown in this video BMW Service - Oilhead valve adjustment procedure by Chris Harris. A few were off a liitle bit but not much. This didn't change the noise.

 

So I continued my online search for knowledge and I come across the left side cam chain tensioner upgrade. I went and checked the bike and it has the part with the 17mm head, so it's never been changed because the new part has a 15mm head. I ordered (literally 5 minutes ago) the Aftermarket Left Side Cam Chain Tensioner Upgrade Kit, it cost me $92 total. Not because I think that will solve the noise, just because I now know the bike should have it.

 

The search continued and I came across mention of the rocker end float. This is not mentioned in the service manual I have and apparently It should be done before adjusting the valve clearances.

 

I found this post "Adjusting rocker end float, and valve clearances" on ukgser.com.  So, I'm going to pop those covers off again and adjust the end float and then check the valve clearances again.

 

Actually, I do have one question. If I do end up loosening one head bolt to adjust the end float, should I go ahead and retorque all the head bolts?

 

  

[dirtrider]

1 hour ago, Dave334478 said:

1997 R1100R 55k mi.

 

This is basically me documenting my troubleshooting not neccesarily asking a question but if you have advice or experiences to add please do.

The bike runs great. After riding for a few miles I hear a loud tapping at idle that decreases as the rpm's increase. It sound like excessive valve clearance. If I let the bike sit and cool for 5 minutes the sound is gone when I start it back up.

 

First, I readjusted the valves using 4 feeler gauges at once as shown in this video BMW Service - Oilhead valve adjustment procedure by Chris Harris. A few were off a liitle bit but not much. This didn't change the noise.

 

So I continued my online search for knowledge and I come across the left side cam chain tensioner upgrade. I went and checked the bike and it has the part with the 17mm head, so it's never been changed because the new part has a 15mm head. I ordered (literally 5 minutes ago) the Aftermarket Left Side Cam Chain Tensioner Upgrade Kit, it cost me $92 total. Not because I think that will solve the noise, just because I now know the bike should have it.

 

The search continued and I came across mention of the rocker end float. This is not mentioned in the service manual I have and apparently It should be done before adjusting the valve clearances.

 

I found this post "Adjusting rocker end float, and valve clearances" on ukgser.com.  So, I'm going to pop those covers off again and adjust the end float and then check the valve clearances again.

 

Actually, I do have one question. If I do end up loosening one head bolt to adjust the end float, should I go ahead and retorque all the head bolts?

 

  

Afternoon Dave

 

Yes, one of the cylinder head nuts on each cylinder head needs to be loosened & then retorqued after the rocker arm end float adjustment. 

 

As for the re-torque of all the cyl head nuts?, Personally, I usually precision mark that one loosened cylinder head nut. Then after re-torque see if it goes back to the exact same clocking.

 

If it goes back to where it was before loosening then I do not re-torque the other cyl head nuts.  

 

I will CAUTION you on adjusting the rocker arm end float-- You can't easily get a feeler gauge around the back side of the rocker arms so if that is the tight spot you can easily get the rocker arms too tight. If you get them too tight (too little end play) you can easily stick a valve when the engine heats up then the  piston can strike that valve & bend it. 

 

Adjust to the loose side not the tight side of specs-- Personally I use a dial indicator to set/adjust the rocker end play as that measures the ACTUAL rocker arm movement. Using a feeler gauge only measure end play in a few places.

 

Added: When you have the valve covers removed use a strong bright light to inspect the cam chain guides. A broken chain guide tip or end can allow a slapping/clacking cam chain.

 

Added/Added: Be sure to re-verify the rocker end float AFTER you re-torque the head nut & bearing bolts-- Final torquing can change the end float settings. 

[Doctare]

  Is it only when in neutral? Does this noise stop when the clutch is pulled in? 

[Dave334478]

1 hour ago, dirtrider said:

Afternoon Dave

 

Yes, one of the cylinder head nuts on each cylinder head needs to be loosened & then retorqued after the rocker arm end float adjustment. 

 

As for the re-torque of all the cyl head nuts?, Personally, I usually precision mark that one loosened cylinder head nut. Then after re-torque see if it goes back to the exact same clocking.

 

If it goes back to where it was before loosening then I do not re-torque the other cyl head nuts.   

 

I will CAUTION you on adjusting the rocker arm end float-- You can't easily get a feeler gauge around the back side of the rocker arms so if that is the tight spot you can easily get the rocker arms too tight. If you get them too tight (too little end play) you can easily stick a valve when the engine heats up then the  piston can strike that valve & bend it. 

 

Adjust to the loose side not the tight side of specs-- Personally I use a dial indicator to set/adjust the rocker end play as that measures the ACTUAL rocker arm movement. Using a feeler gauge only measure end play in a few places.

 

Added: When you have the valve covers removed use a strong bright light to inspect the cam chain guides. A broken chain guide tip or end can allow a slapping/clacking cam chain.

 

Thanks, those kinds of tips are priceless. 

 

I just took it for a short ride to warm it up and then left it idling while I used my trusty (antique extra long wooden handle screwdriver) stethoscope to better pin down the location of the noise.  I made an illustration to show where the noise is the loudest. 
 

 

1 hour ago, Doctare said:

  Is it only when in neutral? Does this noise stop when the clutch is pulled in? 

 

No, no difference in gear or neutral, clutch in or out.

[dirtrider]

13 hours ago, Dave334478 said:

 

Thanks, those kinds of tips are priceless. 

 

I just took it for a short ride to warm it up and then left it idling while I used my trusty (antique extra long wooden handle screwdriver) stethoscope to better pin down the location of the noise.  I made an illustration to show where the noise is the loudest. 
 

Evening Dave

 

Might not tell the specific location as the BMW boxers use thin wall alloy castings so noises travel.

 

Remove the valve covers on a slightly warm engine (thin oil), then rotate the crankshaft until all valves on a cylinder are open. Then try to move the rocker arms with a quick sliding force. See if you get rocker movement & noise. 

 

Caution: if thick cold motor oil then even a large rocker movement won't be very obvious. 

[Michaelr11]

Before you start working on rocker end play....  Once you have carefully adjusted the valve clearance, do a really careful throttle body sync. Our of sync TBs can make a lot of noise.

[Dave334478]

So, I've done the rocker shaft end play and the valve clearances and it still makes the noise. I also installed the updated left side cam chain tensioner.

 

The sound hasn't really changed and I noticed today, it's a little louder when decelerating in gear with the clutch engaged. It's still only after it's warmed up. It doesn't do it when it's cold. It's definitely coming from the left head.

 

I can hear the injectors too but that's a different sound and I'm getting used to it.

[The Fabricator]

 

Aluminum push rods with steel caps.  The caps come loose.  Sometimes.  Remove push rods, clamp tube in vise,  try to twist the caps with pliers.

They can get loose when hot.  Won't fail, but make noise.  

 

My motor makes same noise when hot.  Really hot.  It cools off a few minutes, no noise.

My push rod caps are not loose, via vise inspection.  Have not spent $200 for new.

 

1200 push rods are one piece steel. $45 each. They fit.

 

You can't buy the push rods from a salvage yard.  They sell them with the head.  I tried.

[dirtrider]

9 hours ago, Dave334478 said:

So, I've done the rocker shaft end play and the valve clearances and it still makes the noise. I also installed the updated left side cam chain tensioner.

 

The sound hasn't really changed and I noticed today, it's a little louder when decelerating in gear with the clutch engaged. It's still only after it's warmed up. It doesn't do it when it's cold. It's definitely coming from the left head.

 

I can hear the injectors too but that's a different sound and I'm getting used to it.

Morning Dave 

 

Can you explain the noise in more detail?  Can you tell us if it is once-per revolution noise or a once every 2 revolution noise? (this will tell us if it is valve related or piston/connecting rod related.

 

If you can't easily tell then put a timing light on one side & watch the flashes while listening to the noise (the timing light flashes once per revolution).

 

When you adjusted the valves  were they OK or off a little?  As a rule if the valves are set correctly then the  pushrod end caps won't make any noise. Loose caps mostly cause problems when the loose caps cause the caps to telescope into the alloy pushrod then you end up with excess valve lash.

 

Have you looked at the L/H side plastic  cam chain guides?  If the tip is broken off one of the chain guides then the chain can whip & clatter.

 

We need  you to describe that noise the best that you can  (try to relate it to another noise that we all know), we also need to know if it is a once-per-revolution, or once every-other-revolution, or some other order.   

[Gary E Reynolds]

Check your throttle bodies! Worn TB!

[Dave334478]

Heya Dirtrider,

 

I know it's been months but I don't ride this bike often and when I do it's usually just quick trips around town. I recorded a vid with my phone but never got around to uploading it, I'll do that now.

Last weekend I finally took it for a longer ride, 70mi round trip all freeway. It runs beautiful and rides really smooth but it starts vibrating about 4300 rpm. After a little research I just ordered a Carbtune Pro from the Boneyard so I can do a proper TB sync in it. I'm hoping that'll cure the vibration.

As for the sound, it hasn't changed. I only really hear it when the bike is idling and only after it's warmed up.

The valves were all pretty close but not just right, they are now. There was alot of end play on the shafts, I took care of that too. The vid was taken after all that. I didn't get a good enough look at the guides, it's hard to see in there. I need to pop that cover back off and take a better look. 

PS I'd still like to know how to make videos appear smaller in my posts.

 

[dirtrider]

Quote

 

Heya Dirtrider,

 

I know it's been months but I don't ride this bike often and when I do it's usually just quick trips around town. I recorded a vid with my phone but never got around to uploading it, I'll do that now.

Last weekend I finally took it for a longer ride, 70mi round trip all freeway. It runs beautiful and rides really smooth but it starts vibrating about 4300 rpm. After a little research I just ordered a Carbtune Pro from the Boneyard so I can do a proper TB sync in it. I'm hoping that'll cure the vibration.

As for the sound, it hasn't changed. I only really hear it when the bike is idling and only after it's warmed up.

The valves were all pretty close but not just right, they are now. There was alot of end play on the shafts, I took care of that too. The vid was taken after all that. I didn't get a good enough look at the guides, it's hard to see in there. I need to pop that cover back off and take a better look. 

PS I'd still like to know how to make videos appear smaller in my posts.

 

Evening Dave334478

 

Unfortunately your 4300 RPM vibration is well above the RPM point that a TB sync will do much. 

 

Does that engine noise change if you hold the clutch lever in? 

 

On your engine noise, that does sound pretty trashy but those type of noises are difficult to find or define over the internet as there is just no way to probe around with a stethoscope to isolate the problem area. The other thing we fight with is small computer speakers that don't reproduce the noise the same as we would hear it in person. 

 

It does sort of sound like it is firing frequency but difficult to tell exactly what. 

 

I will listen to it tomorrow on a system with better speakers to see if I can make any sense of it. 

[Jim Moore]

Man, that sounds like a bad cam chain guide.  

[The Fabricator]

Me 2000 R1150GS , 30k miles

I hope you find the cause of the noise.

Sounds like my engine when very hot.  If I let it cool for 5 min, the noise stops.  Clutch in or out, in gear or not. I think I can feel it through the hand grips.

I have checked: 

Rod bearings [replaced], cam chain tensioners, cam chain guides, push rods [original aluminum with steel caps.  I can't get the caps to move holding the shaft in a vise and grabbing the cap with pliers [both  hands] and twisting],  clean the carbon off the piston crowns and head thinking maybe the carbon build up was causing piston/head contact.

I up graded the left cam chain tensioner, install a limiter in the right  cam chain tensioner AND the jack shaft chain tensioner to  prevent 'chain whip' due to failing tensioner.

Thinking maybe the crankshaft was moving axially when running, I pushed against the front crankshaft bolt while running.  [I know the clutch push rod should do this when the lever is pulled, by just in case....]

Cut the oil filter apart looking for chips..nothing unusual.

Starts up, sounds great.    If it idles for 20 minutes, it gets hot enough to clang, like yours.

I think all that's left is radial play in the crankshaft bearings, but I will let it blow up before I go that deep.

Strike out not intentional.

 

[dirtrider]

Morning  Dave334478

 

Dave- I didn't get a good enough look at the guides, it's hard to see in there. I need to pop that cover back off and take a better look. -- Definitely do this just to eliminate that possibility. 

 

I listened to your engine vidio again this morning on my work computer (better speakers) but all that did was enhance all  the other engine noises so I still can't split out your complaint noise from all the other background noises.

 

A mechanics stethoscope is a big help in identifying engine noise source areas (they are not real expensive). 

 

You can use the stethoscope in 2 ways, first is to probe around with the stinger to listen for telegraphing noises transferred through the engine casings (this can sometimes pinpoint the transfer areas). The second way (one that I use a lot)  is to remove the stinger & amplifier then just use the open hose to listen for airborne noise as that can help pinpoint the area of noise origin.  (the open hose tends to only allow the noise in at the hose end therefore blocking out a lot of other peripheral noise like exhaust & combustion noises).

 

Another tactic that I use is I have a couple of old (metallic center) spark plug wires that are cut down to  go between the spark plug & stock spark plug wires. I install those then run the engine. This then allows me to use a screwdriver with a ground wire attached to short out each cylinder to see what if any influence that has on the engine noise.  (never just remove a spark plug wire on  a running  BMW boxer as that can damage the ignition coil)

 

At times I will also unplug each fuel injector looking for a noise change. (this can sometimes help pinpoint piston knock or piston small end noise. 

 

I have also used a timing light to help in identifying  engine noise frequency & timing, if the noise happens at each light flash then that is a once per rev on the BMW 1100/1150  lost-spark boxer engine as it sparks at every piston TDC.  

 

Tracking down engine noises is sometimes a very difficult thing to do (especially on thin casting air cooled engines with all those noise radiating fins & loose tolerances due to expected thermal expansion.

 

It is usually pretty easy when leaning over the running engine to tell lighter ticking or clacking valve train type noise from heavier lower end or piston related noises but  that still doesn't  isolate the noise to one specific area. 

 

   

 

 

 

[Dave334478]

14 hours ago, dirtrider said:

Morning  Dave334478

 

I listened to your engine vidio again this morning on my work computer (better speakers) but all that did was enhance all  the other engine noises so I still can't split out your complaint noise from all the other background noises.

 

Wow, different worlds. I have a 505w 5.1 surround sound system with a 10" sub on my pc that actually goes to 111%. My Moto G6 records in stereo and when I play that vid on my (gaming) PC it sounds, and feels, the same as it does when your standing next to the bike.

 

No home theatre or good earbuds?  I highly reccomend JVC HAFX5W wired earbuds. They cost like $12 and they sound awsome. I could upload the original file to gdrive or mega if you cared to download it and view it on a device with higher quality sound. I'm not asking you to, that's too much to ask. I'm saying I could if you where inclined to offer.

 

All your trouble shooting tips make good sense. I'll go through it all eventually. It's 100+ outside this week and I'm in the middle of refinishing the kitchen table too.

Thanks for the warning on the ignition, I might have done that. I don't have anything that'll reach down that plug tube. I'll hook up a spare plug to move the spark outside the cylinder.

I just don't want to pull that head off unless I really have to. I've got the experience, skill, and most of the (non specialized) tools to tear the engine down and rebuild it if I really had to, just not the desire to, ya know what I mean?

[dirtrider]

10 hours ago, Dave334478 said:

 

Wow, different worlds. I have a 505w 5.1 surround sound system with a 10" sub on my pc that actually goes to 111%. My Moto G6 records in stereo and when I play that vid on my (gaming) PC it sounds, and feels, the same as it does when your standing next to the bike.

 

No home theatre or good earbuds?  I highly reccomend JVC HAFX5W wired earbuds. They cost like $12 and they sound awsome. I could upload the original file to gdrive or mega if you cared to download it and view it on a device with higher quality sound. I'm not asking you to, that's too much to ask. I'm saying I could if you where inclined to offer.

 

All your trouble shooting tips make good sense. I'll go through it all eventually. It's 100+ outside this week and I'm in the middle of refinishing the kitchen table too.

Thanks for the warning on the ignition, I might have done that. I don't have anything that'll reach down that plug tube. I'll hook up a spare plug to move the spark outside the cylinder.

I just don't want to pull that head off unless I really have to. I've got the experience, skill, and most of the (non specialized) tools to tear the engine down and rebuild it if I really had to, just not the desire to, ya know what I mean?

Morning  Dave334478

 

All the mega wahoo speakers 505w 5.1 systems, or other hi-tec audio doesn't really help as my hearing is pretty limited due to age & over half a century of  very loud engines, loud shop noises, &  no hearing protection used when I was young (no-body knew of such things in the 1950's). 

 

But even if I could hear better, even with up level mega audio systems, they magnify the general normal engine noise along with the offending noise, as well as no specific directional input when recording, or any noise change with cylinder shorting,  so it is basically like trying to hear a dime drop during a rock concert. 

 

The problem in using a spare spark plug is you can't easily do that with the engine running & making the noise  (you really want to be able to do a quick disable/reenable/disable reenable) to see how the engine noise is effected. 

 

If you can't figure out an easy way to short the spark then try a fuel injector unplug/re-plug as that will disable that cylinder with the injector unplugged. 

 

There are other things to try, like removing the spark plugs, then rolling the engine over until a piston is at TDC, then roll it a little farther until the piston JUST starts down the cylinder (crankshaft & connecting rod pulling on the piston) then go in through the spark plug hole with a wooden dowel & give the piston a hard push or rap on the wooden dowel with a soft faced hammer. If the piston moves with a knock then something is loose in the rod bearing, piston pin area, or a loose piston fit, etc. 

 

You can also try running a warm-engine wide-open-throttle compression test (with fuse #5 removed) if the compression is real high then you have a good chance of heavy carbon build up in the cylinders.

 

Do use a very strong bright light to look closely at the cam chain plastic  guide tips (make sure that none are broken off).  A broken cam chain guide can make any number of awful sound-of-death engine noises. 

 

Run it with the clutch lever pulled in to eliminate transmission gear rattle, or gear knocking, due to the harsh firing strokes of the large piston 2 cylinder opposed Boxer twin. 

 

Try a straight 50 weight motor oil as test to see if that quiets a loud bearing or excess clearance. 

 

The LAST thing that you want to consider is taking that engine apart until you identify the noise & what is causing it. Once you take the engine apart I doubt that you will find a smoking gun so it is then a VERY EXPENSIVE guessing game that seldom totally cures the engine noise. 

 

I also suggest that you send an oil sample to Blackstone labs  (their web site will tell you how to do that), if you have a real problem inside that engine, in a lot of cases oil-sample lab work   might tell you what to look for (or if there is nothing to look for).

[Dave334478]

I tried unplugging 1 injector at a time. The sound didn't change.

 

I did notice the idle rpm drops a lot more when I unplug the right side then it does when I unplug the left. 

 

Also the left pulls less vacuum at idle but more at 4,000 rpm and higher. I balanced them between 3,000 and 3,500 but I'm thinking I may need to redo it from scratch and get the idle balanced out better.

 

I really need to pop that cover and get a better look at those chain guides. The oil cap started leaking too so I can take care of that at the same time. I already have the o-rings for it, Dan Cata throws them in for free any time you buy something from him. (I just replaced the bobbins in the front)

[Dave334478]

So, I took apart the right side enough to pull the pushrods out and I've got two questions.

 

#1 Are you assuming I have an Inspection Camera, because I do not and, I can not see all the way into the center of the engine to fully inspect the cam chain guides.

 

#2 Should I heat up the (stock aluminum) pushrods and then see if the caps will move? At ambient room temp they do not but then at that temp, the engine doesn't make the sound. After proof reading my post, I realized this is a no brainer, boiling a pot of water now.

 

Update: After 5 minutes in boiling water ( just under 220f ) I can spin one of the pushrod caps. I can't pull it out but it does spin without too much effort. Do you think that's enough to let them be noisy?

 

 

[dirtrider]

39 minutes ago, Dave334478 said:

So, I took apart the right side enough to pull the pushrods out and I've got two questions.

 

#1 Are you assuming I have an Inspection Camera, because I do not and, I can not see all the way into the center of the engine to fully inspect the cam chain guides.

 

#2 Should I heat up the (stock aluminum) pushrods and then see if the caps will move? At ambient room temp they do not but then at that temp, the engine doesn't make the sound. After proof reading my post, I realized this is a no brainer, boiling a pot of water now.

 

 

Afternoon   Dave334478

 

If those pushrod end caps are not actually coming out & you can't easily pull them out then you don't have pushrod issues.  Those make a very light noise at 1/2 crankshaft speed anyhow & your noise sounds much heavier than that.

 

On the cam chain guides, you need to get a strong light down in the guide area (a small 12v light bulb with wires attached  taped to a coat hanger wire or something similar). I have a strong LED on a long flexible cobra-link type deal that  works good.  

 

It's the outer ends of the cam chain guides that usually break off as the center ends don't have much of any overhang. 

[Dave334478]

And it gets weirder ......

 

So, I put it all back together and take it for a short spin around the block. (about 2 miles out here) The only thing that has really changed is the carbs are better synced now. The vibration starting at 4300 is still there but it's much weaker.

 

The sound is still there but, it only does it above 2,000 rpm now. Before, it only did it under 2,000 RPM.

 

So now, the sound is loudest right above 2,000 rpm and it diminishes as the RPM's go up and it totally goes away at idle. This is under no load condition. When I'm riding it, I don't notice it now. I used to notice it when I came to a stop.

 

I'm starting to think it might just be piston slap on that one side. 

 

I know the bike was dropped on that side once (left) because there is some slide damage on that side of the bike in a few places and the left valve cover has the word "Magnesium" cast into it just above the spark plug cover, the right does not, so maybe it was replaced, maybe even more was replaced. The original owner (I'm the 3rd) has passed away so I can't ask him about it.

[dirtrider]

19 minutes ago, Dave334478 said:

And it gets weirder ......

 

So, I put it all back together and take it for a short spin around the block. (about 2 miles out here) The only thing that has really changed is the carbs are better synced now. The vibration starting at 4300 is still there but it's much weaker.

 

The sound is still there but, it only does it above 2,000 rpm now. Before, it only did it under 2,000 RPM.

 

So now, the sound is loudest right above 2,000 rpm and it diminishes as the RPM's go up and it totally goes away at idle. This is under no load condition. When I'm riding it, I don't notice it now. I used to notice it when I came to a stop.

 

I'm starting to think it might just be piston slap on that one side. 

 

I know the bike was dropped on that side once (left) because there is some slide damage on that side of the bike in a few places and the left valve cover has the word "Magnesium" cast into it just above the spark plug cover, the right does not, so maybe it was replaced, maybe even more was replaced. The original owner (I'm the 3rd) has passed away so I can't ask him about it.

Afternoon  Dave334478

 

That 4300 RPM vibration change is probably more related to engine temperature or possibly slightly less oil in the engine after the valve cover removal. 

 

 4300 RPM is WAY to high for the throttle body balance to have much of any effect.

 

From what you posted the other day  (no noise change by shorting cylinders)  piston slap if one the stand-out possibilities.  That can sort of come & go depending on cylinder temperature vs piston temperature & engine working load. 

 

When you don't have the noise allow it to idle in place for time then see if the noise comes back.