cam chain tensioner

[T900]

being trying to get the modified left side tensioner for my 1150 for the past two months, only to be told its no longer available and to use the old type, (it still rattles like the old one).
other gsers helped by referring my to various dealers, but still the same story.
no one knows why the modified tensioner is no longer available??
i am just back from touring france,spain and andorra, a dealer in france told me that the reason for this is, the tensioner is causing premature chain and guide wear , so they reverted to the old type.
bmw are saying nothing in case they are flooded with warranty claims.
i sorted out my rattle by putting a metal rod inside the tensioner spring to stop the piston being pushed back when the engine is off, thus stopping the chain slap at start up, (the rod is measured to give the piston 2mm movement) when the engine starts up normal oil pressure takes over.
my rattle is gone and the engine is so smooth i cant believe the difference,
this very poor service from bmw,

 

[Sea Lion]

I posted a message concerning rattling LHS camchain a few days ago for my 1100.

Last night I replaced the tensioner with a standard replacement. There was some evidence of slight scouring on the old one but wasn't what you would call worn out. However I also replaced the oil with a high quality mineral 20-50 grade oil. Previously I was using semi-synth 10-40.

Have done 100 miles this morning in all conditions and, (touch wood), no rattle. I suspect the oil change had more to do with the solution, but for the sake of £30, changed the tensioner just to be sure.

What grade oil are you using? I was initially advised to use 10-40, but it is outside the recommended temp range and when hot runs like p**s. Also the old tensioner is far cheaper than the 'revised' one so may be worth trying a replacement anyway.

 

[T900]

i fitted a new tensioner and the only difference is the body is couple of mm shorter and the hex head is a 15mm,
it still rattled on start up, i am using castrol gps 10/40, supplied by my local dealer with a full service kit, using heavier oil only goes around the problem, but it does help,
i am an experienced motor technician and never seen a chain tensioner that has no damper or ratchet assembley until i looked at my 1150.
my gripe is they brought out a modified unit that works like a hydraulic lifter, brilliant i say, but they no longer supply it and they tell you to use the old one?????????
the modified unit is still listed on thier parts system and they cannot supply it.
on doing some digging i was told its causing premature wear,
any dealer i spoke to say they no nothing, (bullxxxxe).
i work for a main car dealer and i can pick up the phone for any tech problem, if they cant give me answers they check with the factory,
bmw will do nothing to answer my questions not even reply to phone calls or emails so i done my own mod.

 

[Sea Lion]

So does your mod consist of a simple rod that fits inside the spring that stops the tensioner piston moving in more than 2mm? It would be useful to know in case the problem re-occurs.

On the subject of oil again have you tried changing to 20-50? I would not say it's just getting around the problem, you would just be using the correct oil as recommended for the current ambient temp. If it also stops the rattle then hey, problem solved. I also get the impression most people use 20-50 on this forum.

As far as the GS is concerned, what with cam chain tensioners, fickle abs, side stands that lean too much, broken steering stops if it falls over, I have to ask how on earth did BMW get such a reputation for good engineering?

 

[Sea Lion]

Another thing that crossed my mind is that would it be possible to adapt the existing tensioner to provide more thrust.

I was thinking if you could widen the oil way in and reduce the oilway out you would get more force (this is what happens in the revised/deleted one I beleive). However I'm not sure which hole is which. It appears to be that the oil enters the sleeve through a tiny pin prick of a hole and leaves through the piston slot which appears bigger. It's therfore not surprising little internal pressure builds up. I had wondered about a blob of weld and some neat file work to narrow the slot.

Any one any thoughts on this 'butchery'?

 

[Gecko]

No offence mate but do you really think you can do better than the army of BMW technicians and thier millions worth of computers and equipment . The boxer cam chains rattle - live with it , it's character

 

[(RIP) Kaister]

The boxer cam chains rattle - live with it , it's character

no - its inexcusable in a design from 1923.

its also inexcusable that BMW are so closed about it all.

At least Honda do recalls and suffer the embarrassment when doing cam chain tensioner recalls on nearly all models in the 80's

i think fitting a rod inside is the cure - check on advrider

 

[T900]

the oil feed is not the problem,
when the engine shuts down it tends to stop at a position that leaves the tensioner side of the chain under pressure due to the camshaft position on the valves, because their is no oil pressure when the engine is off, the chain pushes the guide against the tensioner that has only spring pressure inside it, thus forcing the oil inside the tensioner to be forced out through the oil bleed cut out on the piston. all that is needed is a ratchet assembley to lock the piston in place and allow it to adjust outwards only to take up slack from normal wear and tear.
putting a rod inside the spring stops the piston being pushed back, but it will not adjust for wear and tear so i would recommend checking it when doing valve clearances as you can look straight at it when the rocker cover is off.
the chain should not be allowed to slap around the place on start up or at idle speed as this greatly increases wear on the sprockets and valve train, remember 90% of engine wear occurs at start up
if you bought say a 50grand bmw car would you be happy to be told its normal, i dont think so.
its bad technical service from bmw.

 

[Sea Lion]

No offence mate but do you really think you can do better than the army of BMW technicians and thier millions worth of computers and equipment . The boxer cam chains rattle - live with it , it's character

It's not character, just poor engineering and design.

 

[Arbreacames]

the chain should not be allowed to slap around the place on start up or at idle speed
...it's bad technical service from bmw.

I could not agree more with your opinions. If BMW cannot communicate a SOLUTION to knowledgeable people who ask the right questions, how can we hope it will help us with ANY problem?

Before I found out that there was an enhanced tensioner, I also experimented with a rod inside the tensioner and found that a 56 mm rod reduced the play in the tensioner from 10 mm to only 3 mm. The results were excellent, but I was afraid of operating so far outside the intended design. Does the tensioner ever need so much free play? Could the rod grind its way through the end of the plunger or the body? I rode a few hundred kilometers worrying about it until I got one of the enhanced parts.

I also tried to drill a larger fill hole on the spare tensioner body I had bought, but that did not help. Reducing the drain is not easy because you would have to fill a slit, which is not easy to do without welding and machining. Also, you could end with too much pressure on the chain rail.

I remember having read recently that neither the standard nor the enhanced tensioners were being sold anymore, but that there is a new tensioner body that costs the same as the standard one. Can anybody confirm that there is a third, newer tensioner out there? If so, can anybody measure the differences between the original and new?

 

[Arbreacames]

I just found the following information here:

The 11 31 2 325 563 was sold as a "kit", and the "kit" is discontinued. The 4 parts are available seperately, as left tensioner (11 31 7 671 723), spring (11 31 1 341 015), cylinder(11 31 1 340 741) and gasket(07 11 9 963 308). Part # 11 31 1 341 137, described as Left Side Tensioner, is labeled obsolete.

So, how is this new 11 31 7 671 723? Can anybody comment?

 

[T900]

http://www.maxbmwmotorcycles.com/
check out this site for the parts fiche,
when you order the parts seperatly you get the the old type setup,
i bought and fitted it, guess what, it rattles the same as the old one. fitting a rod inside only holds the piston out when the engine is not running, when it is running oil pressure takes over and there is no pressure on the rod,
the dealers think when you order the parts seperatly you get the expensive tensioner that cures the problem,
the now available body is shorter and has a reduced oil feed hole.
it works the same as the old type that drives everybody crazy.

 

[Arbreacames]

Originally posted by T900
when it is running oil pressure takes over and there is no pressure on the rod

The noises at idle speed are from chain slapping and hitting the full travel of the LCCT. A rod prevents that slapping, which means it must be carrying some loads, right?

Originally posted by T900 the now available body is shorter and has a reduced oil feed hole.
it works the same as the old type that drives everybody crazy.

Reduced feed hole and shorter body? Sounds like the opposite of what was needed!

 

[T900]

you may hear a slight click as the engine starts, there should be no noise when the engine is running as the tensioner is pressure feed with oil, if its noisey at idle there could be other concerns ie idle speed to low, throttle balance, or a very low oil viscosity.
you mentioned drilling out the oil feed hole, this should not be done as it will reduce the damping effect, reduce the bleed slot will reduce draining when engine is off,
the new body is shorter by about 4mm, they made the oil feed smaller to increase damping inside the tensioner,