I've just driven back from Aylesbury this afternoon (about 70 miles) and cruised along about 80mph most of the way. After pulling off the motorway, I decided to give me motor a quick blast along the country roads back to my house, so I floored it away from the roundabout in 1st & 2nd gear (right up to about 6200 rpm) and behind me I left the most enormous cloud of blue smoke! The car also didn't pull through the rev range like it should.
So I thought I'd blown something major in the engine or something, and drove home slowly for a further investigation. However, I can now rev the engine right up to the 6500 line, and no smoke at all. I have given it a blast up and down the local roads, and nothing - runs like a dream, not overheating or anything obvious like that.
Anyone any idea what might have happened. I'm a bit dubious about taking it too far in case something bad happens and I get stuck.