Timing chain snapped

[peejay]

My 1200GSA DOHC version broke down last Sunday.
Early thoughts were left hand coil pack, as it was only firing on the right pot.
Fortunately I have extended the BMW warranty so free recovery was sorted back to Bristol Motorrad.

Not coil pack so engine stripped on the left to discover that the timing chain had snapped.
They have never seen one do that before and I've not heard of one going.

So question is does anyone out there know of this happening before and more importantly what might have caused it?

Thankfully the warranty will cover it. Best 30 quid a month I've invested

 

[Norfolk Tiger]

I can't say I have heard of it before,what year and how many miles on the bike?

 

[peejay]

I can't say I have heard of it before,what year and how many miles on the bike?

2010 model and has done 26k without fault.
Has only burnt about 2 litres of oil in that time.

Puzzled as to why it would go, was running sweet without rattle or any tell tale signs. Just let go.

 

[John Armstrong]

I wonder if your chain was made by the same company that made the F800GS and it's little brothers twin, as they seemed to be "problematic" a few years ago.

 

[(RIP) Johno23]

Sounds like a one off fluke
Steptoe would know how common/unusual it is.

 

[patzx12]

It must have made a right racket when the piston hit the valves unless the valves were in the closed position (compression stroke) when the the chain let go.
Did you try restarting it and were there any horrible mechanical noises?

 

[peejay]

It must have made a right racket when the piston hit the valves unless the valves were in the closed position (compression stroke) when the the chain let go.
Did you try restarting it and were there any horrible mechanical noises?

No noise just a sudden loss of power but right cylinder still running. It starts on one and runs! Just sounds like its firing on one!

 

[Steptoe]

Sounds like a one off fluke
Steptoe would know how common/unusual it is.

Very unusual. I've never seen any 1100/1150/1200 with a snapped cam chain.

But seen a few airheads with their timing chains snapped.

 

[Bendy toy]

When my car blew its (work of the devil) cam belt, there was no noise whatsoever - it just stopped. The only clue was an offbeat sound on the starter.

 

[Greg Masters]

It's likely to be a real mess.

Firstly, the chances of all the valves being closed is virtually nil. At the moment the chain let go, the valve train would have slowed quickly (but at a different rate to the piston) rather than stopped dead. Only if you were REALLY lucky would the valve train have stopped in the all closed position in the time it takes for the piston to complete one cycle.

The chain itself might have caused a few problems around the crank sprocket.

It all must have made a fair bit of noise when it let go ...

What oil were you using?

 

[bowser]

So question is does anyone out there know of this happening before and more importantly what might have caused it?

Its a well known fault caused by not using the best first cold pressing olive oil in the engine, you have only yourself to blame ;-)

You need to use Lambda, produced by Speiron Co. in Greece.
"Lambda costs €40.90 (US $54) per bottle or €150 (US $200) in a special gift box. For the truly extravagant, Speiron offers a bespoke, hand-crafted case with two 18k gold plates—one of which, along with the bottle, bears the owner’s name—for a price of €11,000 (US $14,698)."

You know its worth it !!!

 

[davegs]

Its a well known fault caused by not using the best first cold pressing olive oil in the engine, you have only yourself to blame ;-)

You need to use Lambda, produced by Speiron Co. in Greece.
"Lambda costs €40.90 (US $54) per bottle or €150 (US $200) in a special gift box. For the truly extravagant, Speiron offers a bespoke, hand-crafted case with two 18k gold plates—one of which, along with the bottle, bears the owner’s name—for a price of €11,000 (US $14,698)."

You know its worth it !!!

I've always found Mazola ok and cheaper!, have heard that ground peanut oil is better!.

 

[peejay]

It's likely to be a real mess.

Firstly, the chances of all the valves being closed is virtually nil. At the moment the chain let go, the valve train would have slowed quickly (but at a different rate to the piston) rather than stopped dead. Only if you were REALLY lucky would the valve train have stopped in the all closed position in the time it takes for the piston to complete one cycle.

The chain itself might have caused a few problems around the crank sprocket.

It all must have made a fair bit of noise when it let go ...

What oil were you using?

No noise at all! I would have expected a lot of metallic clattering with that end result.
All a bit surreal.

Oil wise Castrol fully synthetic, as used always from new. And it burns very little of it!
That is till I get it back

 

[Bendy toy]

Oil seriously is not relevant in something like this, but that top class cold pressed stuff does look tempting.

These guys however think food grade refined canola (rapeseed) is better. They also say its used as a a base for synthetic lube the esters.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2928512

 

[Steptoe]

It's likely to be a real mess.

Firstly, the chances of all the valves being closed is virtually nil. At the moment the chain let go, the valve train would have slowed quickly (but at a different rate to the piston) rather than stopped dead. Only if you were REALLY lucky would the valve train have stopped in the all closed position in the time it takes for the piston to complete one cycle.

The chain itself might have caused a few problems around the crank sprocket.

It all must have made a fair bit of noise when it let go ...

What oil were you using?

No noise at all! I would have expected a lot of metallic clattering with that end result.
All a bit surreal.

I've had a cam chain break on my old airhead. No noise, just a slight "puff" sound.
No valves damaged, in fact nothing damaged. But i replaced the cam and crank sprockets as a precaution.

 

[peejay]

This is all the damage. Lower cam chain guide. Pin bent means new engine cases or short engine. Both ways bloody expensive, but covered by warranty.
Still no explanation as to why the chain snapped.

Dealer wants to put in new engine as it saves on time, but BMW are trying to push the very slightly cheaper option which incurs mega labour.

Glad Ive got the 800 to use while they bitch it out.

 

[Bendy toy]

If valves don't hit pistons there will be no damage so no need to replace cams. But the broken chain flapping about (and whatever cause it to break) would cause mayhem down in the bowels of the engine.

 

[Pukmeister]

I appreciate that the dealer will fix under warranty, but if it happened outside warranty would new cases be essential or could the bent pin be dremelled in two and removed/replaced along with the chain tensioner blade? Not clear in the photo but has the bent pin been ripped out of the cases causing damage??

 

[peejay]

Like I say, the bent pin is the only damage.

I would have thought in the old days the pin would have been drifted out and replaced, but they say it comes part of the engine casing and they are sold in pairs!

Like I've said from the start, thank god I extended the warranty.

 

[Bendy toy]

If you are allowed to get a close look after the engine is stripped, some detailed pictures of the damage would be great to see. It might even be repairable but main dealers (generally) just replace whole units.