not listened to the file yet, but am now noticing (with door open) that on idle the engine distinctly sounds like a diesel (funny that !), the characteristic diesel chatter is evident. However get to around 1000rpm and above, then this sound disappears completely right through the rev range.
Is yours like this ?
ps just listened now, yours sounds much like mine
Yes, definite diesel crackle at low revs, Oh dear, we are tuned right in now.
its just so much better than it was.