Start-up rattle

[Steve in VT]

My '07 R12R often sits for a week or more between rides, and lately I've noticed it makes a bit of what sounds like tappet noise when first started. The valves were adjusted 3K ago (bike currently has about 9K on the clock), and I don't think they're due for a while yet. My mechanic suspects the cam chain tensioner may be loose, but I'm wondering if it's just a case of the oil draining out of the system. Anybody had a similar experience? And would synthetic oil tend to stay in place better than garden-variety motorcycle oil?

[hjsbmw]

I'm wondering if it's just a case of the oil draining out of the system

That's the explanation I've come to accept. I don't hear it always but if I do then only on the right and for maybe a second. Parking on the center stand vs. side stand *sometimes* seems to have a positive effect. Switching to synthetic didn't fix it for me. Switching from 20/50 to 15/50 *may* have made it happen less frequently. I am thinking about using a 10/50 next to see if that makes a difference.

Edit: I can't recall hearing this when starting the bike in the morning. I usually hear it when I stop briefly and restart, i.e. with the engine warm.

[deilenberger]

This is one of those "many of them do it.." and have been doing it for miles and miles and..

I like Joe's idea of the 10W-50 oil.. but Joe, you might consider Castrol TWS (only available at your friendly BMW car dealer) - made specifically for the S54 M3 engine and the V8 M5 engine - it's a 10W-60 of excellent quality. It's even made in Germany. With a BMW Car Club discount, it's cheaper then BMW's 15W-50 synthetic. Plus it comes in pretty gold colored bottles now..

[famousperson]

Mine has the same rattle. I don't know if it is coming from one cylinder or both. It happens when the bike has been on the center stand, too. Sounds fine just moments later. Synthetic oil didn't change anything, it still rattles. It's such an organic sound I've never worried about it.

[MTBeemer]

My 2007 R1200RT did it when it sat for a few days; my 2008 R1200R does not do it. Both bikes had the same oil in them.