engine knocking loudly

[stross]

hi today i was riding up and down the fosse way when all of a sudden my GS 1200 2007 started knocking loudly on my left hand cylinder side, had to get it recovered by RAC . What could the problem be ?
I have only had the bike for 6 weeks and i thought that the GS was bullet proof ?
Oil level was up normal. No oil pressure light came on, it just started knocking.
Any input about the matter would be very appreciated, As my faith in these bikes are slowly fading .

 

[PaulW21781]

Worst case scenario, could well be a dropped valve...

Did it start to run like a bag of spanners when it went? Or did you just stop it & call the RAC as soon as it happened?

 

[charlie brown]

Air intakes

Have you checked the obvious stuff (sorry if this is egg sucking)

I have had a similar sketch in the past. Check the air in take is marrying up as it should. I know a couple of other 07 owners who have had the left hand side intake come away. It will run extremely lumpy in this scenario.

Fingers crossed, smashed valves are expensive, this aint.....

Good luck

 

[stross]

Hi thanks for the replies I did try to start it Again and it sounded like a bag of spanners in a washing machine

 

[muppix]

May be worth checking the spark plugs are tight. I once had an embarrassing visit to a French workshop to diagnose what I thought were cam problems on my Bandit for this very reason.

Fingers crossed for you!

 

[TeaPig]

Unscrew the centre sparkplug on the LHS. If it's dropped a valve, the end of the plug will almost certainly be mashed.

The noise you describe does point to this unfortunately and although rare, if you do a search in this forum, you'll find a few similar tales of woe.

 

[stross]

thanks i will take plug out later and have a look

 

[stross]

tension spring

h,i got to the bottom of it, my cam chain tensioner spring is missing which means i think that no tension is on the cam chain so when you give it an handful the chain has slipped and put it out of sync which in tern has smashed the valves piston. is it possible for the bike to lose the tension spring and to cause so much damage to the bike? thanks for looking

 

[TeaPig]

h,i got to the bottom of it, my cam chain tensioner spring is missing which means i think that no tension is on the cam chain so when you give it an handful the chain has slipped and put it out of sync which in tern has smashed the valves piston. is it possible for the bike to lose the tension spring and to cause so much damage to the bike? thanks for looking

There's no doubt that if the chain slips on the spockets the valve timing will be lost with potentially disasterous consequences. However, for this to happen due to the failure of the cam chain tensioner would be unusual as the tension is maintained by both spring and oil pressure which pushes a plunger onto the rear of the cam chain tensioner itself. If the tensioner snapped it could cause a serious failure but I've never heard of that happening before.

With such a serious failure it's often hard to piece together the series of events. Have you had the head off yet to see if all the valves are intact? If not, I'd suggest that it's still possible you dropped a valve first which may have prevented a rocker opening fully hence locking the camshaft for moment. Something would have had to give and at this point the chain may have jumped the sprocket and possibly trashed the tensioner.

However, with little to go on it's all speculation. If the tensioner is knackered the chain will be loose and thrashing about. If the valve timing is wrong, the timing marks on the camshaft will be out of alignment. If the head has come off a valve, then there will be a headless valve inside. If the chain tensioner device is broken it can easily be checked by removing it from the side of the engine. You say the spring is missing? It's not possible to see it unless you've taken it out, have you done this or are you just observing that the tensioner blade is slack?

Bottom line is the head needs to come off and keep digging until you've found the full extent of thr horror.

Good luck!

 

[stross]

Cheers as it is still under warranty they can sort it out and I will post what they have found I just hope that when it's fixed a don't get any more problems as I have just purchased a kn filter acropovic can and a wunderlich power box?

 

[socket086]

one small thing when they find that it was a dropped valve make sure that all the bits are there if not at some point in time there will be another bang and a lot of bits and you might be out of warrenty by then. i have a blown engine in the shed that had a dropped valve fixted and 10k later blew up no warrenty lesson learnt the hard way. make sure you have all the bits if they dont show you the bits refuse to take back bike.

 

[stross]

ok cheers i will say show me the bits

 

[APE]

Cheers as it is still under warranty they can sort it out and I will post what they have found I just hope that when it's fixed a don't get any more problems as I have just purchased a kn filter acropovic can and a wunderlich power box?

Stross if you just want a nicer sound fit the pipe and ditch the other bits. If powers your aim you're better off fitting de-cat headers with the pipe - the chip will help but I would still ditch the filter

 

[stross]

Blown again

Well the gs is back the problem was cam chain tensioner spring missing they said and it knocked the timing out and smashed the internals they had it for 5weeks to fix it it came back on Thursday today weather was good so decided to go on the foose way I got 4miles and then the bike lost power and smoke every wear and nearly all the oil gone the smoke was blurry White and lots of it I have now lost faith in my first BMW iv had it since November and used it three times and on two it's blown up I have lost interest in the Kjm super bikes that sold me the bike I thence I will book it in a BMW garage sort it out once and for all this is the first and last time I buy a used bike

 

[littleredrooster]

Well the gs is back the problem was cam chain tensioner spring missing they said and it knocked the timing out and smashed the internals they had it for 5weeks to fix it it came back on Thursday today weather was good so decided to go on the foose way I got 4miles and then the bike lost power and smoke every wear and nearly all the oil gone the smoke was blurry White and lots of it I have now lost faith in my first BMW iv had it since November and used it three times and on two it's blown up I have lost interest in the Kjm super bikes that sold me the bike I thence I will book it in a BMW garage sort it out once and for all this is the first and last time I buy a used bike

Paragraphs or full stops perhaps? Babelfish couldn't translate this...

 

[Spike]

Donot loose heart stross, what has happend to you is very unfortunate BUT no ammount of servicing or polidhing or carful riding could have prented this.
Its a mechanical fault that could happen to a brand new bike with only a couple of miles on the clock.

Be interesting to hear what the next problem was for you with all the smoke and oil loss.

spike

 

[Beemerman59]

Well the gs is back the problem was cam chain tensioner spring missing they said and it knocked the timing out and smashed the internals they had it for 5weeks to fix it it came back on Thursday today weather was good so decided to go on the foose way I got 4miles and then the bike lost power and smoke every wear and nearly all the oil gone the smoke was blurry White and lots of it I have now lost faith in my first BMW iv had it since November and used it three times and on two it's blown up I have lost interest in the Kjm super bikes that sold me the bike I thence I will book it in a BMW garage sort it out once and for all this is the first and last time I buy a used bike

Did you not have this repaired by a BMW dealer under warranty?

 

[st247]

Paragraphs or full stops perhaps? Babelfish couldn't translate this...

 

[littleredrooster]

Cool. I'm glad you understood it.

 

[stross]

New bike

We will never no what the problem was this time. They are changing the bike they are giving me the adventure instead of the gs but no abs. Will this be a problem or not? Cheers