pre-ignition rattle

[Voyager]

Need a little help with diagnosis. With 95K on my R1100RT while not under load at 3500 to 4500 RPM I sometimes hear something like a pre-ignition rattle from the engine. I recently adjusted valves & synched TB's and also reset the ECU. I would normally suspect low octane gas but the pump said 91 and I would expect it under load instead of on a level or downthrottle. Any ideas?

[Softtail]

How long have you had the bike and what gear are you in at 3500-4500 rpm. When you say you are not under a load, I assume you are not accelerating or going up hill. Tell me more!<<<<Softtail>>>>

[Voyager]

I've had it two years and put 15K on the clock. It's usually 2nd or 3rd gear when I'm keeping my RPMs up on busy country or small town roads. It may do it in higher gears, but I doubt I could hear it.

[jrbldr]

I've had it two years and put 15K on the clock. It's usually 2nd or 3rd gear when I'm keeping my RPMs up on busy country or small town roads. It may do it in higher gears, but I doubt I could hear it.

I would tend to agree that those conditions it would not likely be pre-ignition rattle. Based on the description, maybe slack in the cam chains or valvetrain?

[Voyager]

I would tend to agree that those conditions it would not likely be pre-ignition rattle. Based on the description, maybe slack in the cam chains or valvetrain?

 

That's kind of what I was thinking.

 

It goes away if I crack the throttle open or closed, and only happens above 3500 RPM. I may try the updated tensioner but given the cost/benefit analysis, I'm likely to ignore it.

 

This is definitely in the category of "I can live with it", I just wanted to make sure it wasn't foreshadowing any catostrophic failure (detonation) or hastening the ultimate demise of my engine.

 

Thanks for the input!