That chain sound may be clutch chatter from the sound of it. Probably unrelated to the oil issue.



That's a whole lot of oil you're losing. I'm surprised there's only a slight smell of oil.

I would try a 10w30 oil and see what happens. Next few times you top it off, add a bottle of 10w30 and then when you change the oil next use 10w30.


The oil issue shouldn't cause any problems for you in terms of damaging other components, etc... it's the octane thing that has me a bit concerned.