Noise on acceleration when up to temp

[Plodbike1962]

I have just taken delivery of a 2008 R1200 ZRTP. 54500 miles  On acceleration (when up to temp) I get a noise like exhaust header is loose or the timing chain is loose you could describe it as a clatter too. When you come off the throttle you can't hear it. Engine performs as it should. I was wondering about the oil being too thin so will change it tomorrow. Noise does not occur on startup !!!


Has anyone experienced this that can advise possible causes.


Thanks in advance


Grant UK

[milleplod]

Hi Grant, and welcome to the Forum.

First off, keeping it simple, as an RTP, does it have any crash-bars fitted - it's possible something might be loose! Is it rattling at a specific rev range?

Next thing I'd do is to fill it up with some Super Unleaded, assuming you're not already using it of course. If the rattling stops, and you were previously using 95 octane, there's a chance that the anti-knock sensor(s) aren't doing their thing and it's pre-detonation that you're hearing. I've no experience of it though, just a thought.
Have you had a boxer before? If not - and don't take this the wrong way! - it could be that you're riding technique needs modifying! The boxer engine doesn't like high gears/low speeds - asking it to pull from, say, 40mph in top can lead to all sorts of odd noises and vibes!

That's 3 simple things you can check. Next would be to do a service, if one's not been done recently. I'd start with a throttle body sync - this can certainly help a rough-sounding/feeling engine considerably, as can new plugs.Does the bike feel hesitant when accelerating and making the noise? It could be a main coil breaking down under load, and the noise of just one cylinder firing properly would certainly be noticeable, although so would the loss of power!

I'm pretty sure timing chain tensioner noise would be heard at startup, so would rule that out, although someone else may know differently.

Pete

[Plodbike1962]

Hi Peter


Thanks for replying. Yes I have an R1100RT too. This bike does have crash bar ex MET bike. Super unleaded is that normal for these to run on ? bike feels solid and pulls well, the noise is like an exhaust blow from the header like a gasket missing the sort of fut fut fut sound on tickover or when revving. All good from cold start up though.

[milleplod]

BMW recommend 98 octane - the bike will run fine on 95 though as it self-adjusts, albeit with a resultant slight power loss. Knock-sensors will retard the ignition if detonation is detected - if it has 95 in the tank, and the sensors aren't working, you'll get 'pinking' noises. It might be an idea to get the bike put on a GS911 to see if any codes are shown at all.

I'm assuming you've checked the header nuts and other exhaust connections, just in case anything that should be tight isn't? If it sounds quiet when it's cold, the noise could be something that's opening up with heat, although I've never come across an exhaust leak before.....unless something's damaged of course.

I'd have a good look at the crash bar mounting bolts, particularly the lower ones - they're known to work loose!

Pete

[Plodbike1962]

Thanks Pete will do