Engine rattle
Hello guys and greetings from Greece!
I have a 2015 MT-09, which I bought brand new in August last year. A few weeks after, during cold start I noticed a knocking noise. It only lasted a couple of seconds and then just faded away.
I didn’t worry too much to be honest, I felt it was something minor and only came up randomly. I even mentioned it in the first 1,000 km service, the mechanic just said the same and proposed just to keep an eye on it.
As the winter passed by and weather became hotter, it would do it on every single start up. I called the dealer and he said we’d have a look at it on the 5,000 km service, which we did. In-between I started reading around the Internet and the magic words “belt tensioner” came up. So the decision was to replace it on warranty.
The part came and I left the bike at the workshop to have it replaced (had already 6,000 km at that time). Returned the day after, start the bike to go home and there she goes again: tack tack tack… And then faded away again. Both the mechanic and me had that baffled look on our face, couldn’t explain WTF.
We both agreed to monitor it for a couple of weeks. And then it became worse of course: not only it knocked on startup, it just rattled continuously to the point I felt the engine would fall apart in-between my legs.
Straight back to the dealer with 7,400 km on the clock. Now the idea was to replace the 20W-50 oil with a less viscous 10W-40. Still Yamalube, semi-synthetic – Yamaha apparently strictly prohibits full synthetic for this one, don’t ask me how’s that making any sense.
Dealer said the tensioner is actuated by the oil pressure built from the engine, so there was the possibility that thick oil would get a couple of seconds to circulate and therefore the knocking noise on cold start. Thinner oil would sort this out. Of course that doesn’t explain the rattling once the engine is at operating temperature, but nevertheless we had to try something.
Guess what: absolutely nothing changed, it’s even getting worse at higher ambient temperatures (we ‘re almost at 40 degrees Celsius these days). The next step is the Mechanic to contact the official importer in the country and ask for some advice.
Till then, any ideas of what could be wrong? Even if we do change the tensioner again, I don’t think it’s gonna make any difference as it should. Any proposals for you fellow MT-09 riders would be definitely appreciated.
And to make things a bit easier on what’s this noise and how exactly does it sound, I’m attaching a couple of videos for you to see:
https://www.youtube.com/watch?v=0hjUrrZezRw
https://www.youtube.com/watch?v=0gZyqK5qDYg
https://www.youtube.com/watch?v=2Fi9ljRg0ZY
