idle rattling from rear cylinder

[outrigger]

Morning all,

I had my bike out last night for a run to town for dinner. It's been garaged mostly the last couple of months because it's cold and I'm soft. When I do get it out it starts fine, warms up reasonably quickly and runs well (this is all past tense...). On the way home last night I pulled up at the lights and heard a rattling sort of noise that seemed to be coming from the rear cylinder. Only at idle, and maybe very low revs (<1800rpm). Still makes the noise if I clutch in at speed. No noise when accelerating, cruising or engine braking. I ride with plugs in and anything I can hear over the exhaust is significant, so it's not subtle.
For the record, Kreiger mCCTs went in when I got the bike at 70,000km (now at 90,000) and I'm running old style 2bros exhausts. Recently did an oil and filter change with Motul 5100 10W/40.

Power does not seem affected at the low end - I didn't rev high on the way home with the noise because I didn't want to blow anything up, took it easy. Next weekend I will try pulling the valve cover and see what I can see. In thw meantime, any lightbulbs? CCT was my first thought but (a) they can't really fail, it hasn't moved from position and (b) no power loss or grenading.

Thanks team

[VTRDark]

(a) they can't really fail

Unless fitted incorrectly and/or the locknut has worked it's way loose and the tensioner has unwound itself.

It's extremely difficult to diagnose sounds over the net we need as much info as possible and maybe a video clip of the noise.

Where manual tensioners put in as a precaution or after a CCT failure. Has the bike had any history of a past failure. What's you oil consumption like, does the bike burn much oil or smoke much. Loose or broken exhaust gasket and/or seals can cause a rattle. The same with loose drive chain tension. What's the mileage on the bike and have the valve clearances been checked.

Are you sure the sound is from the rear cylinder as sound direction can be very misleading. Is it from the top of the engine or lower down. Maybe use a mechanics stethoscope or long screwdriver blade to try and pinpoint exactly where the sound is coming from.

(:-})

[Wicky]

Check rear exhaust header hasn't developed a leak from manifold area / link pipe connector as this can make disturbing noises.

[AMCQ46]

is the chain touching the linkpipe?

[outrigger]

(a) they can't really fail

Unless fitted incorrectly and/or the locknut has worked it's way loose and the tensioner has unwound itself.

It's extremely difficult to diagnose sounds over the net we need as much info as possible and maybe a video clip of the noise.

Where manual tensioners put in as a precaution or after a CCT failure. Has the bike had any history of a past failure. What's you oil consumption like, does the bike burn much oil or smoke much. Loose or broken exhaust gasket and/or seals can cause a rattle. The same with loose drive chain tension. What's the mileage on the bike and have the valve clearances been checked.

Are you sure the sound is from the rear cylinder as sound direction can be very misleading. Is it from the top of the engine or lower down. Maybe use a mechanics stethoscope or long screwdriver blade to try and pinpoint exactly where the sound is coming from.

(:-})

it's possible that the locknut came loose and the bolt unwound rapidly, but it seems unlikely. I'd love to record the noise, but I'm loathe to start the bike before I've had it apart. I put manuals in as a precaution, I'm not aware of it ever suffering a failure. Bike has 90K so it's getting on. Exhaust brackets and header mounts seem fine, no movement. Chain is relatively new and within spec. Valve clearances have not been checked, but again this is sudden and drastic.

I can't be 100% sure, I may have to try the screwdriver trick. Idling at the servo, with helmet and earplugs I could hear better over the exhaust (loud!) and it definitely seemed to be coming from upper rear.

[VTRDark]

I'd love to record the noise, but I'm loathe to start the bike before I've had it apart.

Sorry I thought you was still riding it but taking it easy. It must be a very bad noise/rattle for you not to want to start the bike.

I would have the cam covers off for visual inspection (chain tension) and while your in there you might as well check the valve clearances with that sort of mileage.

Use the following guide for MCCT installation.
http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=28583

Ih and welcome to the forum.

(:-})

[outrigger]

Ok I pulled the rear cam cover tonight to see what I could see. Everything looked fine, tensioner blade seems intact, tension adjuster not significantly moved. I re-tensioned front and rear mCCTs. Valve clearances are a tiny bit tight but not so much that I'm going to do anything about it. Exhaust manifold (rear) also seems very snug, no movement. Can't rule out slight leak I guess, but I'm iffy about that, didn't sound anything like exhaust. So nothing to show for a few hours work. I'll fire it up on the weekend, I don't live in the sort of neighbourhood where cranking the two-brothers at 9.30 goes down well on a weeknight. I will record a video, too, and see if I can pinpoint the noise

[VTRDark]

Mmmm Yeh video of the sound will help. I have been following your thread over the pond too

It seemed like too deep of a noise to be that sort of vibe, i got a feeling of a bigger part, or more movement

You have checked the simple/obvious things and ruled out. Other issues that could occur (especially with high mileage) would be lower down Clutch area, bearings or even an overly slack/stretched primary drive chain.

What's the bikes oil consumption and temperature like, It may be worth doing a compression test, piston rings could be a possibility or even a blown/failing head gasket, detonation causing spark knock! though these noises usually would not be a deep sounding noise Just thinking out aloud and throwing some possibilities out there.

Like I said in an earlier post it's difficult to diagnose sounds over the net. Lets have a listen.

(:-})

[outrigger]

Started the bike this arvo. Who can guess what I'm going to say...?

No noise. I'll have to come back to this one, this thread isn't dead yet...

[lloydie]

That's some good news .
Least it wasn't bent valves

[VTRDark]

As Lloydie said good news. Obviously something has changed since whipping the cam covers off and checking adjustment. Maybe it was the adjustment itself Either way you have the end result you wanted.

(:-})

[8541Hawk]

As it only happens at idle there is a good chance that it is just the clutch rattling around.

Mine does it from time to time. It is very noticeable on my bike as I have the damping rubber removed from the clutch cover.
So she does do her Ducati impression now and then.

Time to get the stethoscope (or a screw driver) out and track down where the noise is really coming from.

[nt1980]

+1 to the above clutch may be

[outrigger]

As it only happens at idle there is a good chance that it is just the clutch rattling around.

Mine does it from time to time. It is very noticeable on my bike as I have the damping rubber removed from the clutch cover.
So she does do her Ducati impression now and then.

Time to get the stethoscope (or a screw driver) out and track down where the noise is really coming from.

Would you still hear it with the clutch pulled in & in gear?

Other thing I thought was maybe because it was cold I wasn't getting the noise