Evening all, after a 10 minute spirited drive this evening, I noticed something strange, the engine/exhaust note went very deep (and "gurgley", almost tractor like) and the engine felt very sluggish. I crawled the extra mile home - and opened up the bonnet, there appears to be a slight knocking noise and the oil is down to about 4mm showing on the dip stick (it wasn't this low when I bought it a few days back) - edit: an after thought, that was immediately after stopping, a lot of oil would have still been around the engine - this may not be a cause for concern? Now, it sounds a bit to me like