Dead R1100RS - Troubleshooting Tips?

Did you do a compression check?

"The bike ran strong until it quit, without any catastrophic sounds/feelings, etc. Even if compression were gone on one cylinder, it would still start/run on one (roughly of course, but it would run...)."


It looks like you have covered most of the basics and some of the advanced diagnostic testing but I can't see any indication that you ran a compression check on the bike or checked the engine timing. You have fuel, air and fire but if sequence isn't timed properly you won't get ignition. I would check the mechanical timing on the bike to make sure the timing chain has not slipped a tooth or two.

First if you haven't already, pull the valve covers and check the valve clearance (make sure the valves on both cylinders have proper valve movement) and then check the engine timing (Piston, valve and ignition sensor) then run a compression test on the bike. Slipped timing or a chunk of carbon holding the exhaust valve open can do exactly what you described in your first post (sudden failure, backfire when cranked, won't start) even if it was only one side of the motor, consider the age of the bike, mileage and known problems with the timing chain components along with possible carbon buildup in the combustion chambers.

PGlaves said:

It might be a good idea to go back and check the timing of the HES plate. The easy wat to do that is to have the key on and rotate the engine by hand on the pully bolt at the front. Each time the pistons reach Top Dead Center - exactly TDC - the fuel pump should cycle on. If not EXACTLY on the OT mark when the pump turns on, take the pulley back off and readjust the HES.

Click to expand...

Paul has probably timed Voni's RS umpteen times so I'm sure this will probably work fine but it doesn't work on an 1100RT. No idea why, it just doesn't.

This timing method works perfectly on an 1150 engine which has a Motronic 2.4 ECU but on my 1100RT with a Motronic 2.2 it does not work at all. The pump won't cycle. Other than using a timing light the only method of static timing my 1100 is to use a home built timing box or use an inductive timing light on the spark plug wire and time a warmed up engine idling at 1100 RPM to the "S" mark in the flywheel housing view port.

Here's a link to Dana Hager's simple timing and hall sensor test box: http://advwisdom.hogranch.com/Wisdom/oilhead_timing_box.pdf

Yes We Can! (Think political slogan...)

PGlaves said:

It might be a good idea to go back and check the timing of the HES plate. The easy wat to do that is to have the key on and rotate the engine by hand on the pully bolt at the front. Each time the pistons reach Top Dead Center - exactly TDC - the fuel pump should cycle on. If not EXACTLY on the OT mark when the pump turns on, take the pulley back off and readjust the HES.

Click to expand...

Paul,
I trotted out to the garage, at sure enough, using the fuel pump cycling test, it did indicate that the HES was a bit off. But this is now the least of my worries. THE PLOT THICKENS...

happy wanderer said:

Paul has probably timed Voni's RS umpteen times so I'm sure this will probably work fine but it doesn't work on an 1100RT. No idea why, it just doesn't.

This timing method works perfectly on an 1150 engine which has a Motronic 2.4 ECU but on my 1100RT with a Motronic 2.2 it does not work at all. The pump won't cycle. Other than using a timing light the only method of static timing my 1100 is to use a home built timing box or use an inductive timing light on the spark plug wire and time a warmed up engine idling at 1100 RPM to the "S" mark in the flywheel housing view port.

Here's a link to Dana Hager's simple timing and hall sensor test box: http://advwisdom.hogranch.com/Wisdom/oilhead_timing_box.pdf

Click to expand...

Wanderer,
That is a good bit of information. I'll tuck that away in the archives. Happily, a '00 R1100RS fuel pump does cycle at TDC. But for the REALLY exciting news, read on...

(Movie Score with Music of Impending Doom...)

Okay, so I'm hunkered down next to the lovely RS, with a socket on the crank pulley bolt, ratchet in hand, about to turn the engine over to perform Dr. Paul's fuel pump cycling/HES fine tuning, when I think: "Maybe I should pull the plugs to make turning the engine easier..."

Nah... Let's just see how it goes...

Hmm... as I'm turning the engine, I think: "Man, this IS turning like the plugs are out - BUT THEY'RE IN! (Long extended groan...). So I dig out the compression tester. Brace yourself...


Right side


Left side

What the heck!?! Did the cam chain break?

This has me scratching my head... I just looked at the part numbers for the 1100RS ECU and the 1100RT ECU and they are identical. Both our bikes are 2000 models and the RS and RT engines are also identical. I am starting to wonder if I was doing something wrong when I replaced my last hall sensor. Next time I have the front cover off I'm going to have to try this again as it sure is a nice easy way to time your bike on the side of the road or in a campground someplace.

Do you have the upgraded timing chain tensioner?

Need to pull the valve cover off and see what is happening with the valves and timing chain.

But, you are close to finding out what is wrong.

Upgraded Tensioner?

23217 said:

Do you have the upgraded timing chain tensioner?

Need to pull the valve cover off and see what is happening with the valves and timing chain.

But, you are close to finding out what is wrong.

Click to expand...

I've had the RS for about 2 years. To my knowledge, it does not have the upgrade tensioner. I think it's time to peek under the valve covers and see what I can see...

I had an R1100RS that failed in similar circumstances and no compression on one side.

One of the exhaust valves had a chunk missing most likely due to combustion chamber crud getting wedged under the face.

I fear you have suffered the same fate. It isn't going to be a cheap fix if so...

Have/had you ridden in the rain or washed the bike shortly before encountering the initial problem. We once had an issue where riding in the rain ingested sufficient moisture into the snorkel, filter, and air box to cause carbon bits to break loose in the combustion chamber. When Voni exited the Interstate and stopped at a stop sign the engine died and defied restarting. I found bits of hard carbon lodged at the valve seats, holding the exhaust valves open.

Even without moisture, a wide open throttle pass as described could cause some carbon to break loose - just like we used to do to Grandpa's Desoto or Buick.

Other typical causes of sudden low compression usually involve funny clanking noises.

At this point, I would be pulling the valve covers and having a good look to make sure all the good parts are still all good. After that, I would do a cylinder leak down. That would narrow me to a jug issue or a timing issue.

Check the clearances (gaps) on the valves - especially the exhaust valves - on the side with low compression. If the gaps seem larger than specified that would signal that the valves, or more likely one valve, is being held open.

Funny Clanking Noises...

PGlaves said:

Have/had you ridden in the rain or washed the bike shortly before encountering the initial problem. We once had an issue where riding in the rain ingested sufficient moisture into the snorkel, filter, and air box to cause carbon bits to break loose in the combustion chamber. When Voni exited the Interstate and stopped at a stop sign the engine died and defied restarting. I found bits of hard carbon lodged at the valve seats, holding the exhaust valves open.

Even without moisture, a wide open throttle pass as described could cause some carbon to break loose - just like we used to do to Grandpa's Desoto or Buick.

Other typical causes of sudden low compression usually involve funny clanking noises.

Click to expand...

In my early days of riding, I traveled all over creation without the slightest thought of hearing protection - and my audiologist says it was my undoing. So these days, I don't mount up without something stuffed in my ears. The problem with that is, it makes diagnosing those funny clanking sounds a bit more difficult.

But deafness aside, my butt is intimately involved with the bikes rhythms and vibrations, and I never noticed any violent disturbances in that department. I would love to discover that a dislodged piece of carbon is responsible for all this.

No, on the day she died, it was picture-postcard blue Colorado skies. And I don't recall washing her before heading out. I'll take a peek at the valve clearances... Thanks!

I hate being correct here.

Sorry about that Bwanajames, before you get discouraged or start thinking of parting out take a deep breath and then find out the extent of the damage. From the compression number on the left side I would guess the chain slipped and you bent the exhaust valve, right side may just be carbon or the cylinder had been washed by gas causing a bad seal for the rings. Take your valve covers off and check the valves on both sides, you may be able to loosen and dislodge the exhaust header on the left side to see if its carbon or a bent valve holding it open.

Its not the end of the world if the timing slipped and a valve bent. Its just a question of how attached to the bike you are. By your posts I would guess your very handy with the tool box and your not afraid to open things up to have a look. If its a slipped chain and bent valve you might consider a used motor and rebuild yours while you still get to ride the bike or you can just swap it out and call it a day.

Between the BMWMOA Flea Market, IBMW, BoneYard and Recycle you can easily find the stuff you need to get it back up in running. Keep us posted

Do you still have the Charcoal Canister connected on your bike?

If I recall we had another member who had the carbon flow from the charcoal canister into his left cylinder combustion chamber until it stopped the bike. He had quite a bit of carbon in the chamber.

I have also noticed that on my personal bike that water is getting into the outer gas tank ring and going down the drain hole. The gas tank rubber gasket is okay. It seems like a engineering flaw to me. The water will then flow into the charcoal canister (if connected), and then into the engine. My wife's Subaru has a sensor in the charcoal canister which will shut off the car if the charcoal canister gets too full. I guess Subaru Engineering figures that this is better then carbon flowing into the engine. Her car has shut off twice leaving her on the side of the road. Both times, the gas tank was 1/4-to-1/2 full. So, it wasn't fuel causing the problem. But, it rained a couple days prior one time and the day before the other time. So, even if you didn't encounter rain recently, this may be the cause. All of this is assuming that your bike has carbon stuck in the exhaust valve. The charcoal canister is not hard to disconnect.

In any event, you need to get your left cam chain tensioner upgraded. About $75 for parts. Easy to change out. But, determine the root cause of your present problem before doing this.

Cylinder leak-down test is easy and dead accurate.

Before I got myself all wound up about a blown engine, I would do a cylinder leak-down test. It will tell you if the cylinders are capable of holding air and if not, you will find the leak, bent/burnt valves or worse. If it holds air, then you are dealing with a timing issue and at that point, you determine if the chain to cylinder slipped or crank to cam chain slipped.

A good cylinder leak-down test should take you about an hour. If you find the problem, great. If not, checking the timing using the over-lap method will get you down to the chain you need. That should take another two hours.

I can't see these chains jumping easily but, I have seen a good back-fire make them jump.

Chris_d said:

I had an R1100RS that failed in similar circumstances and no compression on one side.

One of the exhaust valves had a chunk missing most likely due to combustion chamber crud getting wedged under the face.

...

Click to expand...

This happened to me, left me stranded. For the life of me I could not figure out what the problem was. Don't know if this is your problem, I hope not as it was very costly to repair.

Parting Out?! I'd Rather Part with My Wife! (Oops... I already did...)

69zeff65 said:

Sorry about that Bwanajames, before you get discouraged or start thinking of parting out take a deep breath and then find out the extent of the damage. From the compression number on the left side I would guess the chain slipped and you bent the exhaust valve, right side may just be carbon or the cylinder had been washed by gas causing a bad seal for the rings. Take your valve covers off and check the valves on both sides, you may be able to loosen and dislodge the exhaust header on the left side to see if its carbon or a bent valve holding it open.

Its not the end of the world if the timing slipped and a valve bent. Its just a question of how attached to the bike you are. By your posts I would guess your very handy with the tool box and your not afraid to open things up to have a look. If its a slipped chain and bent valve you might consider a used motor and rebuild yours while you still get to ride the bike or you can just swap it out and call it a day.

Between the BMWMOA Flea Market, IBMW, BoneYard and Recycle you can easily find the stuff you need to get it back up in running. Keep us posted

Click to expand...

Parting Out?! I'd rather part with my wife! (Oops... I already did...) Despite the year and mileage, she looks like she just rolled off the show-room floor. It was my first Beemer, and riding it is better than sex. I'll strip it down to the last nut & bolt if I have to - but it will be fixed!

Handy with a toolbox? Ha! By necessity I suppose. (You guys are doing a great job of saving my ass so far...) My dad always said "A bike will make a mechanic out of you..." Man, was he right. Here is my winter project on my RT.







Fortunately, I've got a couple of trusty (?) steeds for back-up... (Dead RS in the background)

I am happy I was correct with my "handy with a tool box" comment.

I do have a suggestion regarding the first order of business though. Before you get deep and distracted with repairs on the RS I would respectfully suggest you install the upgraded timing chain tensioner in your RT and GS, this forum is an outstanding source of information on that upgrade as far as parts and procedure to get it done.

When I met my wife I had 9 bikes with one residing in my living room/great room. Over the five years of our union the bike population in the house has fluctuated between 2 & 4 at a time (currently 2) and the overall bike population has only slightly increased to 25, some post wars, /2's, airheads, a few Triumphs, some Kaw's, a couple oil heads and the most recent being an R Nine T. My problem is a place to keep them. My wife is helping me erect my new steel building/shop so I can have a little more room to play and work with my toys.

I'm truly sorry to have gone off topic but GOSH DARN she is the best, all I did was make sure I bought her a bike to call her own and keep her first bike in the living room after I picked up her second bike.

Keep us posted

Got Chain!

Well, I'm happy to report that when I pulled off the valve covers, I didn't have a naked sprocket staring back at me. But I did expect to find some irregularities with the valve clearances. Strangely enough, they were in the ballpark.

Perhaps I've got a chunk of valve missing (suggested earlier) and that's the reason it's not sealing...


Left side (with 10 psi of compression)


Right side (with 88 psi of compression)

Have you turned it through a complete revolution

Can you turn the motor over smoothly and slowly while you watch the valve action? Watch the rockers, chain and the tops of the valves to see if anything looks odd.

I would think that if a valve were stuck open the clearance on that valve would be wide open even if were just a small piece of carbon the greater clearance should be noticeable.

If you don't see anything obvious do the suggested cylinder leak down test that has been suggested by "dieselyoda" and find out where the leak is, valves or piston.