So, I’m riding to work on my trusty 2003 BMW R1100S Wednesday morning and while sitting at a stop light idling I vaguely hear a pretty awful sounding engine knock through my helmet and the NPR morning news feed piped into my ears from my iPod Nano. At first I think it may be from the oldish Pontiac 4-banger sitting next to me at the light, but just before the light changes I’m pretty sure it’s coming from my motor.
As I press on to work it seems to go away once the engine is at speed and I don’t hear it when I pull into the parking lot at work so I assume it was just a momentary anomaly.
Heading home everything seems fine, no unusual noises, knocking, etc. However, as I’m headed down Old 41 the “low oil pressure light” comes on: oh shit! That’s never good on a BMW oil head motor as it means the crank is being starved for oil. It takes me a about a minute to get to a place where I can pull over, but as soon as I pull over and the engine goes to idle the light goes out. I check my sight glass to verify that there’s oil in the engine, which there is… about 1/4 quart low but still plenty. I fire up the engine and everything seems fine so I continue to ride the final 5 miles home. As I’m riding along Stilesboro Road the “oh shit” light comes on again… but just briefly so I press on to the house. As I’m putting the bike in the garage the engine knock I heard earlier in the day returns, but without the low oil pressure light. I shut the think down and cuss… a lot.
Just surfing the web, there are all kinds of possibilities: rod knock, the cam chain tensioner could have come apart, it could be the throttle body, etc. None of those are good things when you’re no longer equipped with the experience, patience and tools needed to properly begin the diagnostics / engine tear down process to troubleshoot the noise on the somewhat qwerky BMW motors. So, I’ve got an appointment to drop the bike off on Thursday at Bobby Woolridge’s BMW of Atlanta shop near work. Of course, riding the bike to work and dropping it off is like playing with fire so I’ll have to borrow my friend David’s trailer to drop it off.
I’m guessing this isn’t going to be an inexpensive visit. If it’s a minor issue that can be tackled without going down to the crank it’ll be around $600 – $1,000. If it’s more serious than that… $2,000+. Not a happy camper. Hell, I’d probably be better off looking for an engine out of a wrecked R1200S! Wouldn’t that be a neat upgrade. Oh well, we’ll see what happens.