I think my engine may have let go

[Antares]

Evening all,

I was on my way home this afternoon going up north on the M1 when less than 30 miles into the trip suddenly after a downshift bike started rattling like crazy, pronounced vibration in the bars and it was tied to engine RPM.

I don't think it's something critical because the bike still ran OK and accelerated just fine, as soon as I managed to turn around I also tried revving the bike out and it seemed to get to redline with no problems just a lot of rattle. I noticed the spring on the left side where the cable goes into the clutch actuating rod was unclipped but pulling the clutch in or holding the rod did nothing for the rattle.

On the way back I noticed that the bike is maybe a bitt juddery and lurchy (nothing extreme, maybe placebo even) but shifts also felt like they weren't "timed" right, shift took a long time and didn't feel smooth.

The noise seems to be coming from the right hand side so my first thought was maybe the cam chain tensioner came loose, but when I had that happen once before (my fault for not snugging it up) the vibration sound would go away above 5000rpm or so completely. That was also a much more soft rolling type noise whereas this is very sharp rattle.

I only have 1 solid guess and that's maybe the cams slid in relation to the cam gears. When I was doing service on it about 2000 miles ago or so the cams were slightly out of phase and needed adjustment, I can only think maybe there is some issues with torqueing it there and the cams slipped a rather large amount, hence the rough shifts and potential rough running. I can't imagine that being the cause of the rattle though unless the bolts come out or something.

Weirdly when I got home I checked the oil in the sight glass and there was a thick bubbly layer on top, not like condensation foam/beer like foam, but like dishsoapy water kinda bubbles.

Only other ideas are maybe waterpump or oil pump but surely for the latter there'd be a warning light and oil pressure issues?

Bloody annoying, just fitted new road 5s today and was ready to have some fun if the weather was decent...

Any ideas are welcome, I just don't wanna open it up until I get a list of things to look at. The idea of a new engine doesn't sound pleasing, even if they can be had for cheaper than some OEM footpegs 

[smithy]

If it still reves ok it's more than likely the cam chain rattling...has it had the "silver" colored tensioner assembly fitted..?? Or even better, a manual one.??

Rockers can't really slip sideways on the cams unless they break, they sit on a shaft at one end, so highly unlikely if it still revs freely. If the cams have slipped in relation to the cam gears, you'd probably have bent valves, there's not much give each way on these engines. Just one tooth out is enough to cause all sorts of grief.

All this is just me thinking out loud though.

https://www.realoem.com/bmw/enUS/showparts?id=0D03-EUR-02-2017-K49-BMW-S_1000_XR_0D03,_0D13_&diagId=11_5330

Will be interesting to see what your actual issue is...

Smithy.

[Antares]

Originally Posted by smithy

If it still reves ok it's more than likely the cam chain rattling...has it had the "silver" colored tensioner assembly fitted..?? Or even better, a manual one.??

Rockers can't really slip sideways on the cams unless they break, they sit on a shaft at one end, so highly unlikely if it still revs freely. If the cams have slipped in relation to the cam gears, you'd probably have bent valves, there's not much give each way on these engines. Just one tooth out is enough to cause all sorts of grief.

https://www.realoem.com/bmw/enUS/showparts?id=0D03-EUR-02-2017-K49-BMW-S_1000_XR_0D03,_0D13_&diagId=11_5330

Smithy.

Hey, yes it has a manual tensioner, that has not come loose, what i mean about the cams slipping is the actual camshafts in the slots on the cam gears. They are oval slots that allow a little forward and backwards movement of the cams, it's at most 5° adjustment which probably isn't enough to cause pistons to meet valves but enough to throw timing and fuelling in for a bit of a loop. When I did the service I had to move the cam gears a fair amount to get both cams in phas and it did make the engine run a BIT smoother that's the only reason I'm saying it.

[orbits]

I’m wondering if something in the clutch assembly has failed / come loose / cracked. My logic being…
- Engine revs / pulls ok, so probably not fuelling or timing related.
- Vibe is related to engine rpm, so nothing gearbox or final drive related
- the oil foaming may well be just that caused by the increased vibes
- It started on a downshift and now you say it’s not changing gear as cleanly.
- If pulling the clutch in changes nothing maybe that narrows it down to the engine/driven side of the clutch.

Just my idea… go on, pull the clutch cover off 

[smithy]

Originally Posted by Antares

Hey, yes it has a manual tensioner, that has not come loose, what i mean about the cams slipping is the actual camshafts in the slots on the cam gears. They are oval slots that allow a little forward and backwards movement of the cams, it's at most 5° adjustment which probably isn't enough to cause pistons to meet valves but enough to throw timing and fuelling in for a bit of a loop. When I did the service I had to move the cam gears a fair amount to get both cams in phas and it did make the engine run a BIT smoother that's the only reason I'm saying it.

Fair enough....however, if the cams have slipped in the gears, that still wouldn't explain the rattle....unless as you have mentioned, a bolt has fallen out and caused some internal damage we don't know of.

If the cam phase is too far out the engine will not start as the "cam/crank sensor sync" would be out.

As mentioned, it will be interesting to see what it is.

Smithy.

[smithy]

Originally Posted by orbits

I’m wondering if something in the clutch assembly has failed / come loose / cracked. My logic being…
- Engine revs / pulls ok, so probably not fuelling or timing related.
- Vibe is related to engine rpm, so nothing gearbox or final drive related
- the oil foaming may well be just that caused by the increased vibes
- It started on a downshift and now you say it’s not changing gear as cleanly.
- If pulling the clutch in changes nothing maybe that narrows it down to the engine/driven side of the clutch.

Just my idea… go on, pull the clutch cover off 

Good thoughts Sir..!

Smithy.

[bazzer]

Biggest bit of advice is not to start it again until you have done some investigation.

[Winger]

Originally Posted by orbits

I’m wondering if something in the clutch assembly has failed / come loose / cracked. My logic being…
- Engine revs / pulls ok, so probably not fuelling or timing related.
- Vibe is related to engine rpm, so nothing gearbox or final drive related
- the oil foaming may well be just that caused by the increased vibes
- It started on a downshift and now you say it’s not changing gear as cleanly.
- If pulling the clutch in changes nothing maybe that narrows

Just my idea… go on, pull the clutch cover off 

What he said and before that...is there anything in the oil.... and what we are into currently is just a guessing game.

In situations like this....the one thing that never gets mentioned but it what runs the show...’How much you got in the bank and do you intend keeping the bike long trrm’ plan A is above but with parts prices being what they are a very close plan ‘B’ is a motor, cheapest I see on eBay is a £Grand, when I say motor...either for parts or a straight swap depending on what you find.

I say the above as my K1200r Sport lunched itself last year so been there done that.

Hope you are lucky...but even with my bad memory do not remember many X/R’s lunching themselves on here.

[AdzventureXR]

Clutch baskets in RR have been known to be a problem. Usually clutch release should see if this is the case. Drop the oil and look for any metallic parts

[Antares]

Alright lads, dropped oil , clutch cover off timing cover off, oil was clean, no chunks of metal or anything worrying just a tiny tiny amount of fine ferrous dust but that's normal and to be expected, havent taken clutch basket out, but the oil pump chain behind it is awfully loose, but normally they aren't tight with the engine off and therefore not worrying. What is thought is this:




Bottom gear looks awfully tight with almost nor backlash and seems to be discoloured from friction, especially at the tip of the teeth...

I'll take the clutch basket off but in the meantime something to ponder.