cam chain tensioner upgrade r1150

[The Fabricator]

2000 R1150 GS.  30k miles.  The engine was making a noise which sounded like a cam chain tensioner failure. I know the tensioners are spring loaded with oil pressure assist. I know the left tensioner drains when the engine is stopped due to the cylinder pointing down.  That explains the clacking upon start up.  I know there is an upgraded left tensioner with a check valve incorporated to prevent draining.  I replaced the left tensioner with the Beemer Boneyard upgraded unit.  I think the engine is quieter, but there is still a 'tack, tack' noise.  I checked for loose push rod ends [steel caps pressed into aluminum tubes].  I clamped the push rods in a vise, gripped the caps with pliars [2 hands], and tried to spin the caps. No spin. I adjusted the rocker end float to zero plus a little [I could the oil squeeze out at the ends when I translate the rocker on the shaft].  No change in the noise.  I cut the oil filter apart [I do this sometimes when I do oil changes].  Nothing remarkable.  

 

So what about the right cam chain tensioner?  Well, the left BBY tensioner does not fit because LEFT AND RIGHT ARE DIFFERNT.  Any way, why can't the right fail?  There aren't any upgraded right side tensioners.  If I plug up the bleed hole in the right plunger, will that provide enough 'boost'?  Find a stronger spring?  If I order the OEM parts, will I get upgraded parts?  Any one have any experience?

 

 

 

Edited March 23, 2019 by The Fabricator

[dirtrider]

6 hours ago, The Fabricator said:

2000 R1150 GS.  30k miles.  The engine was making a noise which sounded like a cam chain tensioner failure. I know the tensioners are spring loaded with oil pressure assist. I know the left tensioner drains when the engine is stopped due to the cylinder pointing down.  That explains the clacking upon start up.  I know there is an upgraded left tensioner with a check valve incorporated to prevent draining.  I replaced the left tensioner with the Beemer Boneyard upgraded unit.  I think the engine is quieter, but there is still a 'tack, tack' noise.  I checked for loose push rod ends [steel caps pressed into aluminum tubes].  I clamped the push rods in a vise, gripped the caps with pliars [2 hands], and tried to spin the caps. No spin. I adjusted the rocker end float to zero plus a little [I could the oil squeeze out at the ends when I translate the rocker on the shaft].  No change in the noise.  I cut the oil filter apart [I do this sometimes when I do oil changes].  Nothing remarkable.  

 

So what about the right cam chain tensioner?  Well, the left BBY tensioner does not fit because LEFT AND RIGHT ARE DIFFERNT.  Any way, why can't the right fail?  There aren't any upgraded right side tensioners.  If I plug up the bleed hole in the right plunger, will that provide enough 'boost'?  Find a stronger spring?  If I order the OEM parts, will I get upgraded parts?  Any one have any experience?

 

 

 

 

 

 

 

 

Morning  Fabricator

 

The OEM 1100/1150 L/H side cam chain tensioner could drain back after shutdown so the updated (anti drain back  piston) tensioner from the 1200 hexhead is used (usually referred to as the updated tensioner)  as that usually cures the start-up clacking.  Everybody refers to the later L/H tensioner as the updated part but in reality it isn't an updated part for the 1100/1150 engine, it is a 1200 tensioner that just happens to fit the 1100/1150 engine

 

The R/H side doesn't need an anti drain back  piston tensioner as it sits in the engine inverted so it can't/won't drain back & empty of oil after shut down.

 

As a rule the R/H side never clacks at start-up  as it simply can't drain back after shut down, BUT there is a spring inside the R/H side that holds some static tension on the chain until oil pressure builds up & fully tensions the R/H chain. If the engine just happens to stop with some valve spring tension on the R/H side cam lobes in the reverse direction then that can slowly force some oil out if the R/H side as it will ever so slowly push the tensioner  piston back into it's bore.

 

You didn't fully explain (IF) the clacking noise that you are chasing is ONLY after cold-soak start-up or is there on hot engine operation????????-- This can make a big difference in what we chase as the problem.

 

If you are chasing a general rattling/light clacking sound on warm engine then 'THAT' is a very difficult thing to isolate & eliminate.

 

There are many smaller reasons (actually some not so easy to fix) that you can hear a clacking on hot engine.  

 

So start with the cam chain guides-- Use a strong bright light & inspect the cam chain guides for chipped or broken ends (a cam chain guide with a broken end can give you a clacking that is difficult to isolate & very difficult to repair).

 

Next, look at the cam chain guides for deep chain wear or excessive position location from nominal (the farther the movable rail moves the less force that the tensioner internal spring has on the rail (see next sentence).

 

In the past I have had s-o-m-e luck in lowering or removing hot engine light clacking of the R/H side by adding small brass shim washers to the base tension spring (the more wear on the chain rail the more shimming that can be used). The main player on proper chain tension is the oil pressure on the piston but the internal spring does add some basic additional tension. (at least this is something easy to try anyhow)  

 

Now we get into (lets say very difficult territory)-- There is also a hydraulic chain tensioner on the front accessory shaft drive chain. This is a voodoo area as it is difficult to access & very difficult to diagnose. I have found a number of older 1100/1150 engines that exhibit front accessory shaft chain rattle. Everything up front is small, short, & close tolerance. (IF) the problem is in the front chain area then if real lucky you can find a witness area where the chain is ever so lightly contacting the engine case due to chain stretch or lack of proper tensioning (usually not that lucky though). I have seen cases where chain,  sprockets & the front tensioner are replaced & there is 'STILL' some chain noise on hot engine. The good news is I haven't ever seen any failures up front, just annoying noise.

 

Back to cyl head area-- If you are pretty sure that the clacking noise is  engine speed then look for front chain area or once-per-rev things, if you are pretty sure that the clacking is 1/2 engine speed then look for things in the cam drive area, or valve actuation area.

 

At the cyl head area-- look for loose valves in their guides (difficult to tell with valve spring pressure on the valves & valves seated).  Then at each valve check the elephants feet for varying lash by precision checking/ setting the valve lash, THEN rotating the elephants foot 1/4 turn (just the foot not the stem) then re-checking the lash (do this for a full 360° rotation of the foot.  I have seen some older engine elephants foot dissimilar wear that causes lash variation as the foot rotates.

 

Check all the elephants feet adjusters for being about the same height above the rocker arm. If you find one or more that are higher or lower than the others then investigate & find out why.

 

Other, even more difficult things to find is a camshaft with a worn lobe on the take-up ramp . Non-hydraulic lifter camshafts have a gentle take-up ramp ground into the cam lobes to gently/slowly take up the valve lash BEFORE the fast lift part. If this ramp area wears then the valve lash is instantly taken up causing a clack. (just about impossible to find without a degree wheel & a known non-problem engine to compare to).

 

The fuel injectors also make  ticking/clicking sounds so make sure that you aren't just hearing the fuel injectors inject.

 

The other thing to keep in mind is that the BMW 1100/1150 boxer engine is basically air cooled (oil cooled on just specific points) so they are loud as there are no water cooling jackets to insulate engine noise & lots of finned alloy to radiate engine noise. The engine is also basically out in the open with the rider sitting right on top of it (go open the hood on your car then revv the engine).

 

If you ride a BMW boxer bike then ear plugs are your best friend as they keep the engine noise worries at bay.

 

 

[dave_a]

Good one,  DR.

I'll only add:

"Noise is not a warrantable defect" ….right in there with "leakage, weepage, and seepage"

Keep up the excellent guidance!

[The Fabricator]

This is an update to my original posting of March 22.

I did inspect the cam chain guides.  All looked normal.  I cranked the engine [spark plugs out,grounded] about 20 revolutions while watching the left upgraded tensioner and right stock tensioner.  The upgraded tensioner has been in service about 200 miles.  The engine noise is still there.  The is a clack clack after the engine is fully warm.  It seems most pronounced when decelerating.  The intensity varies.  It is quiet when cold.

 

While cranking, I watched the left upgraded tensioner piston start with a 5mm? stroke, that reduced to a 1mm? stroke after 20 revolutions.  The right stock tensioner piston started at about 10mm? and reduced to 5mm? after 20 revolutions.  I soldered up the bleed hole in the piston.  The tensioner piston stroke reduced to 2mm?  

Not satisfied, I fabricated a bolt to prevent the piston from retracting.

With the tensioner spring removed and the valves closed, I positioned the bolt so there was still a slight bit of slack on the chain.  I installed the spring.

The noise is still there, although maybe reduced.  I have not had a chance to test ride the bike on a long ride yet.  I am not encouraged.  I think the jack shaft tensioner will be next.

 

I had the front engine cover off a decade ago [I installed a bigger generator from a car] but I don't remember exactly what it took to remove it.  Can the generator stay?  

 

 

 

 

 

 

Edited June 30, 2019 by The Fabricator
check for typos and clarity

[dirtrider]

1 hour ago, The Fabricator said:

This is an update to my original posting of March 22.

I did inspect the cam chain guides.  All looked normal.  I cranked the engine [spark plugs out,grounded] about 20 revolutions while watching the left upgraded tensioner and right stock tensioner.  The upgraded tensioner has been in service about 200 miles.  The engine noise is still there.  The is a clack clack after the engine is fully warm.  It seems most pronounced when decelerating.  The intensity varies.  It is quiet when cold.

 

While cranking, I watched the left upgraded tensioner piston start with a 5mm? stroke, that reduced to a 1mm? stroke after 20 revolutions.  The right stock tensioner piston started at about 10mm? and reduced to 5mm? after 20 revolutions.  I soldered up the bleed hole in the piston.  The tensioner piston stroke reduced to 2mm?  

Not satisfied, I fabricated a bolt to prevent the piston from retracting.

With the tensioner spring removed and the valves closed, I positioned the bolt so there was still a slight bit of slack on the chain.  I installed the spring.

The noise is still there, although maybe reduced.  I have not had a chance to test ride the bike on a long ride yet.  I am not encouraged.  I think the jack shaft tensioner will be next.

 

I had the front engine cover off a decade ago [I installed a bigger generator from a car] but I don't remember exactly what it took to remove it.  Can the generator stay?  

 

 

 

Afternoon Fabricator  

 

If you go back to the spring in the tensioner then open that small hole back up,  that hole is there to quickly bleed the trapped air out after engine starting. If that hole plugs then that side can clack for a few minutes until the air works it's way out. 

 

Have you set checked/set the rocker arm side play? Personally I use a dial indicator instead of the commonly used feeler gauge as a dial indicator shows the TRUE side play where as a feeler gauge only shows the gap at the spots that you can get access to.

 

As for your (non OEM) generator staying, I can't say without seeing the mounting but if mounted like a production alternator then you should be able to leave it in place.  

 

Have you checked the valve lash on each rocker arm including rotating the elephants foot about 90° at a time until it has spun the full 360°? (I have seen the elephants foot wear in one place but the valve check ends up being done with foot in another clocking).

 

Do all of your rocker arm adjusters  have about the same number of threads showing above the nuts? If not that is an indicator (push rod issue or ???)

 

How are your valve guides as far as wear goes ?  A PITA to check but if nothing else found then might be worth the effort.  

 

Another test-- remove both side spark plugs, then rotate the pistons to TDC, then rotate slightly more until the pistons just start down the bores,   then insert a wooden dowel in through the spark plug holes to touch the pistons, then use your hand to give the wooden dowel a good hit (if pistons move down the bore slightly or clack then you  possibly have worn wrist pins.

 

BMW boxers are noisy engines so finding above average engine noise is difficult (especially that darn front accessory shaft chain). The good news is even the noisy ones seem to run forever & a day.   

[The Fabricator]

This is an update.  2000 R1150GS 30,000 miles.  There is a clack in the engine when it is hot.  Maybe there when cold, but not pronounced. I can feel it in the handle bars.  I have not put a lot of miles on this bike as I am fearful of damaging something due to the knock.  I have ridden it around 1000 miles, about 100 miles at a time.

I have replaced the left cam chain tensioner,  modified the right tensioner [see previous post], adjusted the valves, adjusted the rocker end play to nil, throttle body shafts are tight, the steel ends are tight in the aluminum push rods.

I removed the front engine cover to expose the timing chain.  I modified that tensioner with a rod inside the piston that would limit the piston retraction.  I adjusted the rod length so there is slight chain slack.

The noise is still there.

It just seems like a rod knock noise and the feeling in the handle bars.......so....

 

I can feel the scratches when I drag a screw driver across them.

Is this enough to make noise?  Anybody know?

I am used to seeing scratches on the piston from bearing bits, but these pistons did not have any marks.

 

That cam chain sprocket bolt was really tight.  I have read about people stopping the crankshaft with the rear brake and tensioning the chain and maybe breaking a guide.  I looked for a tool to hold the sprocket, but no go.  I fabricated a tool.  It took 2 tries.

The first tool.  It was not robust enough.  When I installed it and applied torque, it split.

So I made a ring and attached the handle at the weakest point so the gusset would re-enforce the weak area.

Those bolts were tight.  They let loose with a SNAP !

 

I calculate the torque to break the bolts loose 

Handle length 1.5 feet x 30 lbs force [push on bathroom scale to gauge force] = 45 ft-lbs.  This is conservative as the handles are a little longer and I think I squeezed the handles together more than 30 lbs force.  The tension on the chain is 45 ft-lb divided by .10 foot [sprocket radius] = 450 lbs tension.  Also conservative.

[dirtrider]

8 hours ago, The Fabricator said:

 

It just seems like a rod knock noise and the feeling in the handle bars.......so....

 

 

I can feel the scratches when I drag a screw driver across them.

Is this enough to make noise?  Anybody know?

I am used to seeing scratches on the piston from bearing bits, but these pistons did not have any marks.

 

 

 

 

Morning  Fabricator   

 

Difficult to tell anything from the pictures. Looks like a little dirt got through the oil filter & got into the bearing area.

 

The rod bearing shells are not worn through the first layer so that is a good thing.

 

As for the scratches, those alone won't make the bearings knock but excess clearance will so you will either need to mike the crank journals then re-install the rod caps with bearings then mike the inside of the torqued rod bearings.

 

Or (carefully) reinstall rods on crankshaft using Plasti-Gauge, then measure the Plasti-Gauge crushed width, then compare to the package chart. (probably find the most wear with rods oriented just past TDC).

 

I don't know if you can tell much but you might try turning the crankshaft until the rod journals are all the way out then slightly farther around , then reach in & try moving the rear of crankshaft laterally looking for a clunk or movement in the crankshaft.

 

Big difference in sound  between a rod knock & a chain rattle.  

 

 

[The Fabricator]

2000 R1150GS 30,000 miles

It had been a while since I wasted any more time chasing this noise.  I figured I would just let it blow up then attack it.

I have addressed ALL the suggestions mentioned in replies.

 

Just to 'refresh' the topic, this noise is a 'clang' like a rod, happening when the engine slows down from a throttle chop. I can't really hear it when I'm riding faster than a walk.  I stop, gun the engine to 2k, chop, clang, clang, clang.  [Probably more than 3 clangs].  No chips in the oil filter, rod bearings not worn to copper [now new and clang the same.] Chain guides ok,  rocker end float nil, throttle body shafts tight, push rod end caps, cam lobes, so on.

 

There was a suggestion that carbon build up on the piston crown was striking the head at the squish band.  It maybe looked like it, so I cleaned it off.

 

Clang still there.

 

The clang happens 3 bars and above.

 

Now I wonder about the catalytic converter internals.  That might fit with the clang being temperature related.  I bang on the converter with a plastic mallet but cannot reproduce the sound.  

Anyone have any experience with the cat internals failing this way?  Engine runs normal. 

[dirtrider]

1 hour ago, The Fabricator said:

2000 R1150GS 30,000 miles

It had been a while since I wasted any more time chasing this noise.  I figured I would just let it blow up then attack it.

I have addressed ALL the suggestions mentioned in replies.

 

Just to 'refresh' the topic, this noise is a 'clang' like a rod, happening when the engine slows down from a throttle chop. I can't really hear it when I'm riding faster than a walk.  I stop, gun the engine to 2k, chop, clang, clang, clang.  [Probably more than 3 clangs].  No chips in the oil filter, rod bearings not worn to copper [now new and clang the same.] Chain guides ok,  rocker end float nil, throttle body shafts tight, push rod end caps, cam lobes, so on.

 

There was a suggestion that carbon build up on the piston crown was striking the head at the squish band.  It maybe looked like it, so I cleaned it off.

 

Clang still there.

 

The clang happens 3 bars and above.

 

Now I wonder about the catalytic converter internals.  That might fit with the clang being temperature related.  I bang on the converter with a plastic mallet but cannot reproduce the sound.  

Anyone have any experience with the cat internals failing this way?  Engine runs normal. 

 

Evening Fabricator

 

Is this a new noise or a remnant of the original. You were chasing a clack now you seem to have a clang sound.

 

If it is a defined clang (not a clack or thunk)  then possibly the clutch  diaphragm spring is loose (does holding the clutch lever in make a difference in the noise?)  A loose diaphragm spring doesn't hurt anything).

 

Or possibly a post-fire issue inside the exhaust system  (is your TPS set correctly so you are seeing full  fuel shut-off on dropped throttle?). Any signs of an air leak into the exhaust system? Like a leaking header gasket, or loose joint, or crack at rear of cat (some do this), or a rust hole in the muffler. 

 

We can't hear the noise so all we have to go on is your description so make that as accurate as possible.

 

The BMW boxer engines are loud with lots of noise so you can drive yourself crazy chasing the noises. A lot of new BMW oilhead boxer owners think their engines are coming apart at the seams so chase noises then eventually get used to the noises over time so just ride the bike with nothing ever happening. (you very very seldom hear of a BMW oilhead boxer engine failing  & the very few that have failed usually leave debris trail in the oil filter long  before failure).  

 

Any chance the noise is coming from the transmission area? Lots of internal free spinning gears as the trans is a constant mesh. Trans noise is usually quiet when cold but becomes louder as the gear oil thins out.  

 

 

[The Fabricator]

2 hours ago, dirtrider said:

 

Evening Fabricator

 

Is this a new noise or a remnant of the original. You were chasing a clack now you seem to have a clang sound.

 

If it is a defined clang (not a clack or thunk)  then possibly the clutch  diaphragm spring is loose (does holding the clutch lever in make a difference in the noise?)  A loose diaphragm spring doesn't hurt anything).

 

Or possibly a post-fire issue inside the exhaust system  (is your TPS set correctly so you are seeing full  fuel shut-off on dropped throttle?). Any signs of an air leak into the exhaust system? Like a leaking header gasket, or loose joint, or crack at rear of cat (some do this), or a rust hole in the muffler. 

 

We can't hear the noise so all we have to go on is your description so make that as accurate as possible.

 

The BMW boxer engines are loud with lots of noise so you can drive yourself crazy chasing the noises. A lot of new BMW oilhead boxer owners think their engines are coming apart at the seams so chase noises then eventually get used to the noises over time so just ride the bike with nothing ever happening. (you very very seldom hear of a BMW oilhead boxer engine failing  & the very few that have failed usually leave debris trail in the oil filter long  before failure).  

 

Any chance the noise is coming from the transmission area? Lots of internal free spinning gears as the trans is a constant mesh. Trans noise is usually quiet when cold but becomes louder as the gear oil thins out.  

 

 

Definitely engine related [not trans  because it doesn't matter what gear, moving or not].  Specifically, have you encountered a cat failure that makes a noise?

[dirtrider]

10 hours ago, The Fabricator said:

Definitely engine related [not trans  because it doesn't matter what gear, moving or not].  Specifically, have you encountered a cat failure that makes a noise?

 

Morning  Fabricator

 

I have seen a few noise related cat failures but only on the 1100 bikes, I haven't ever seen a noise related cat failure on the 1150gs  with the twin inputs.  (but that doesn't mean that yours isn't an issue).

 

I have seen 1150gs muffler internal failures with rusted out internal baffles & loose internals. 

[njl4]

Good morning Fabricator, Did you happen to look at your throttle bodies? The bronze bearing go bad and the throttle body plates clack as you sit and idle. Last winter I rebuilt mine as both bearings had excessive slop and I keep hearing that clacking sound when Idling. If you search this forum you will find a few write ups on the subject. I thought I had a rod knock or piston slap. just a thought that you might want to look at.

 

[The Fabricator]

4 hours ago, njl4 said:

Good morning Fabricator, Did you happen to look at your throttle bodies? The bronze bearing go bad and the throttle body plates clack as you sit and idle. Last winter I rebuilt mine as both bearings had excessive slop and I keep hearing that clacking sound when Idling. If you search this forum you will find a few write ups on the subject. I thought I had a rod knock or piston slap. just a thought that you might want to look at.

 

Mine are tight.

[basri]

 

Hi, this my first post, i am Basri, from Turkey.

 

97 r1100gs, 42000 miles. I have egzactly the same rattle on the rh side cylinder. Tryed most of the things you have tryed, today pulled out the rh side tensioner and cleaned it. Rattle is still there.

 

Did you solve the problem ?

 

Thanks..

 

Basri..

[dirtrider]

Quote

 

Hi, this my first post, i am Basri, from Turkey.

 

97 r1100gs, 42000 miles. I have egzactly the same rattle on the rh side cylinder. Tryed most of the things you have tryed, today pulled out the rh side tensioner and cleaned it. Rattle is still there.

 

Did you solve the problem ?

 

Thanks..

 

Basri..

 

Morning basri

 

With all the engine revving it is difficult to define the engine noise from the exhaust noise & other engine noises. 

 

You either need to get something on the exhaust to route the exhaust noise farther away from the phone, or listen to the engine with a mechanics stethoscope. I usually use a mechanics stethoscope with the stinger removed (just an open hose) to listen around on the engine to try to define the exact location the noise is coming from. 

 

If you think the noise is cam chain related then you can try removing the tensioner gasket ring  then also  shimming the spring on the R/H chain tensioner with a small washer. (if you remove the tensioner gasket washer then use a little gasket sealer on the tensioner threads to prevent oil leakage). On older BMW boxers you can get some cam chain guide wear so even with a good functioning tensioner it sometimes won't put enough tension on the guide to prevent chain slap. 

 

Also look CLOSELY at the tips of the chain guides, those are easily broken due to engine work. If a guide tip is broken that can allow chain noise.  

 

Also don't discount the front chain, I have seen a number of those make noise due to wear, chain hitting front case, tensioner wear, etc. It is VERY difficult to find, define, isolate a front chain noise. Front chain noise seldom causes any engine issues it is just irritating to hear all the time.  

 

Have you checked the rocker arm end play (side play)? If you have excess rocker arm end play that can give a pretty defined clack.

 

Piston slap is also a possibility as well as piston pin clack  (piston pin clack is very difficult to isolate & define). 

 

Your 1997 is probably late enough to not have 2 piece push rods  but I'm not 100% sure on non U.S.A. motorcycles.

 

You will probably need to try to use a hose to your ear (or better yet a mechanics stethoscope) then try to define EXACTLY where that noise is coming from on the engine.

 

If you have a timing light then you might  put that on one side spark plug wire, then run the engine  while looking at the timing light flash. Your BMW 1100 engine has a lost spark ignition system so you get one timing light flash on every crankshaft revolution. 

 

If you get a timing light flash at every clack then your noise if a once per revolution (so most likely not valve train related), if your clack comes at 1/2 the flash rate then it is most likely valve train related. The cam chain noise can go either way as a flopping chain can just rattle, or it can be in relation to valve spring loading/unloading. 

 

At times I have even towed a motorcycle with an automobile (with trans in gear, ignition off)  to listen without the cylinder firing to see if/how that effects the engine noise. 

 

Finding hidden engine noises on the BMW boxer engines can be extremely difficult at times, especially if coming from a piston or front accessory chain area.  

[basri]

19 hours ago, dirtrider said:

Morning basri

 

With all the engine revving it is difficult to define the engine noise from the exhaust noise & other engine noises. 

 

You either need to get something on the exhaust to route the exhaust noise farther away from the phone, or listen to the engine with a mechanics stethoscope. I usually use a mechanics stethoscope with the stinger removed (just an open hose) to listen around on the engine to try to define the exact location the noise is coming from. 

 

If you think the noise is cam chain related then you can try removing the tensioner gasket ring  then also  shimming the spring on the R/H chain tensioner with a small washer. (if you remove the tensioner gasket washer then use a little gasket sealer on the tensioner threads to prevent oil leakage). On older BMW boxers you can get some cam chain guide wear so even with a good functioning tensioner it sometimes won't put enough tension on the guide to prevent chain slap. 

 

Also look CLOSELY at the tips of the chain guides, those are easily broken due to engine work. If a guide tip is broken that can allow chain noise.  

 

Also don't discount the front chain, I have seen a number of those make noise due to wear, chain hitting front case, tensioner wear, etc. It is VERY difficult to find, define, isolate a front chain noise. Front chain noise seldom causes any engine issues it is just irritating to hear all the time.  

 

Have you checked the rocker arm end play (side play)? If you have excess rocker arm end play that can give a pretty defined clack.

 

Piston slap is also a possibility as well as piston pin clack  (piston pin clack is very difficult to isolate & define). 

 

Your 1997 is probably late enough to not have 2 piece push rods  but I'm not 100% sure on non U.S.A. motorcycles.

 

You will probably need to try to use a hose to your ear (or better yet a mechanics stethoscope) then try to define EXACTLY where that noise is coming from on the engine.

 

If you have a timing light then you might  put that on one side spark plug wire, then run the engine  while looking at the timing light flash. Your BMW 1100 engine has a lost spark ignition system so you get one timing light flash on every crankshaft revolution. 

 

If you get a timing light flash at every clack then your noise if a once per revolution (so most likely not valve train related), if your clack comes at 1/2 the flash rate then it is most likely valve train related. The cam chain noise can go either way as a flopping chain can just rattle, or it can be in relation to valve spring loading/unloading. 

 

At times I have even towed a motorcycle with an automobile (with trans in gear, ignition off)  to listen without the cylinder firing to see if/how that effects the engine noise. 

 

Finding hidden engine noises on the BMW boxer engines can be extremely difficult at times, especially if coming from a piston or front accessory chain area.  

Dirtrider, thank you for your time and effort for writing such  detailed advices.

 

I will check all your advices but the rocker arm area.

 

To remove the valve cover i need to remove the crash bars, which is a torture. In last 30 days, i adjusted the valves twice in order to stop this rattle, now i am too lazy to go thurough this crash bar distress again.

 

Last time i set the valves, i could not fit even the thinest feeler gage in to rocker arm gap at TDC, so there is no rocker arm free play at all on both side. May be i checked it on a wrong place, i dont know. But  left it as it is because i dont have a torque wrench.

As soon as i possess a torque wrench, will remove valve cover again.

 

Once more thank you for your precious information, after all if i come to a conclusion, will report it here..

 

Basri...

 

 

[dirtrider]

3 hours ago, basri said:

Dirtrider, thank you for your time and effort for writing such  detailed advices.

 

I will check all your advices but the rocker arm area.

 

To remove the valve cover i need to remove the crash bars, which is a torture. In last 30 days, i adjusted the valves twice in order to stop this rattle, now i am too lazy to go thurough this crash bar distress again.

 

Last time i set the valves, i could not fit even the thinest feeler gage in to rocker arm gap at TDC, so there is no rocker arm free play at all on both side. May be i checked it on a wrong place, i dont know. But  left it as it is because i dont have a torque wrench.

As soon as i possess a torque wrench, will remove valve cover again.

 

Once more thank you for your precious information, after all if i come to a conclusion, will report it here..

 

Basri...

 

 

Morning basri

 

Depending on the feeler gauge thickness that you used they might be too tight, or were checked incorrectly. 

 

The specification is:  a  minimum of .05mm (.002"), & maximum of .40mm (.016").

 

The  .40mm (.016") is a little on the loose side as you can get some clacking with that much end play. 

 

For me personally the .05mm (.002") is a little too tight on an older engine with miles on it as you can't measure all the way around the rocker arm so if it is at the minimum of .05mm (.002") where you CAN measure it then it could possibly be tighter on the back side where you can't get your gauge in. 

 

Personally, I set the rocker arm end play using a dial indicator as a dial indicator measures ACTUAL rocker arm movement not just the end gap that you can get to. And even then I usually set to a loose .003" (.076mm).

 

You never want to set them tight as that could slow the valve return to seat & allow a piston to hit a valve. 

 

In a lot of cases you can just put the piston to TDC (compression) then move the rocker arms sideways. If you feel a lot of rocker arm movement then it is worth checking. If they all only move just a little (but DO move) then that area is probably not where your noise is coming from. 

 

Figuring out if the clack is at crankshaft speed (once pre revolution), or at 1/2 crankshaft speed (valve train speed) can make the job of tracking engine noises easier (sometimes).

 

But you also have to keep in mind that things that usually knock only on the firing stroke (like a piston pin or piston slap) can fool you as those will typically only make noise at every other stroke.  

 

You also should check the valve lash  in a few different places in the elephants foot rotation. The elephants foot doesn't always wear evenly in it's socket so in some cases can be tight at one clocking & be loose in another. I usually check in 3 different clocking's. Nothing precise in the clocking, I just check the lash, then spin it about 1/3 then another check, then spin it about another 1/3 & check again. 

 

 

[Lowndes]

I've always found a stethoscope to be very accurate at pinpointing where a noise is (or is NOT) coming from.  It works on just about any kind of noise, piston slap, bearings (plain, roller, and ball), tappets and valves, etc.  A clicking valve can be identified quickly without even removing the valve cover.  Rod journals can be a bit of a challenge because they can't be accessed directly.

 

It doesn't have to be a store bought 'scope, either.  A wood dowel, or even better is a long screwdriver with a hard plastic handle.

 

It's interesting just to listen in on an engine running.  You listen to a few good bearings whirring away and a few valves ticking happily, then find an unhappy bearing or valve train junction and there is no doubt about it.

[dirtrider]

48 minutes ago, Lowndes said:

I've always found a stethoscope to be very accurate at pinpointing where a noise is (or is NOT) coming from.  It works on just about any kind of noise, piston slap, bearings (plain, roller, and ball), tappets and valves, etc.  A clicking valve can be identified quickly without even removing the valve cover.  Rod journals can be a bit of a challenge because they can't be accessed directly.

 

It doesn't have to be a store bought 'scope, either.  A wood dowel, or even better is a long screwdriver with a hard plastic handle.

 

It's interesting just to listen in on an engine running.  You listen to a few good bearings whirring away and a few valves ticking happily, then find an unhappy bearing or valve train junction and there is no doubt about it.

Morning  Lowndes

 

Mechanics stethoscope is a great diagnostic tool. 

 

On the thin alloy casting (no water jacket)  BMW boxer engines internal noises telegraph to the castings & covers fairly easily, & sometimes for a long ways,  making pinpointing the noise root location more difficult & at times impossible. 

 

Unless you can get the stethoscope stinger directly on the item making the noise then it difficult to tell exactly where it is coming from. 

 

On the BMW boxers I usually have better luck using the stethoscope with the stinger & diaphragm assembly removed then using just the open hose to locate engine or transmission noises. It won't tell you what it is but in a lot of cases the open hose will pinpoint the location much better than using the stethoscope stinger on the engine case, engine cover, or other casting. 

 

Next time you are chasing a boxer engine noise, try it, it might surprise you on much better the open hose isolates the noise location. 

 

At times I will even add a longer hose to the stethoscope (again no diaphragm amplifier or stinger) then ride the motorcycle with the hose located in different areas on the engine. This way is kind of tricky as the open hose will easily pick up wind rush so the open hose end must be oriented in the correct direction & away from air flow or muffler noise. 

 

I was chasing a knock in a (water cooled)  650 single a while back, it was loud but the noise sounded loudest on the bottom of the engine casting using a stethoscope with the stinger & diaphragm attached, obviously it was also loud on the cylinder & cylinder head but also just as loud on the stator housing. Just about the same noise everywhere on the engine but still slightly louder on the bottom of the engine.

 

With the stinger & diaphragm removed not much noise from the engine's bottom or stator cover but loud as heck in the cylinder & lower head area. I ran my bore camera down through the spark plug hole & saw some streaking on the cylinder walls in line with connecting rod travel. Those markings plus the noise changing with engine temperature I'm pretty darn sure it is piston slap making the engine noise. I haven't taken it apart yet as the owner is still deciding if he is just going to ride it as-is & live with the noise or put money into an older motorcycle. 

 

 

 

[Lowndes]

Thanks, Dirtrider.  Never tried the open hose but I will.

 

It always amazed me that on a 4 or 6 cyl auto engine you can clearly distinguish between each valve thru the valve cover, which means the sound has to travel thru the air (engine gasses) from a tappet to the valve cover, then the 'scope.  They will quickly pinpoint a bad bearing in a belt idler or tensioner.  

[dirtrider]

35 minutes ago, Lowndes said:

Thanks, Dirtrider.  Never tried the open hose but I will.

 

It always amazed me that on a 4 or 6 cyl auto engine you can clearly distinguish between each valve thru the valve cover, which means the sound has to travel thru the air (engine gasses) from a tappet to the valve cover, then the 'scope.  They will quickly pinpoint a bad bearing in a belt idler or tensioner.  

Morning Lowndes

 

Yes, on an external components that you can actually get the stinger on then that is probably the best way to pinpoint the noise as it is direct into the diaphragm/amplifier then into the ear.    Stinger works good on things alternator bearings as it is a direct contact type thing. 

 

It's those remote internal engine noises that seem to be much easier to pinpoint location (not component but location) using the open hose method. 

[Skywagon]

When I was growing up and had noisy valves on a car, my dad would use a yardstick as his stethoscope; Then pull the valve cover, tighten until the noise went away, then back it off a notch. It was a very high tech solution with exacting red neck standards. 

[King Herald]

17 hours ago, Skywagon said:

When I was growing up and had noisy valves on a car, my dad would use a yardstick as his stethoscope; Then pull the valve cover, tighten until the noise went away, then back it off a notch. It was a very high tech solution with exacting red neck standards. 

 

Thats how some guys still do hydraulic lifters on old cars. Buddy of mine did my old Chevy hot rod motor the same way when I couldn't get rid of a noisy tappet. Valve covers off, piece of  cardboard wedged to stop too much oil spraying everywhere, motor idling, and back each tappet off until it clacked, then pinch it down a quarter turn.