I rather unwisely gave the mig a good thrashing on the A1 on the way home from watford last night - it is a ten year old car with 126k miles on it, after all - should really be a bit more careful with the old girl, rather than racing her against kids in saxos.
About two miles from home the oil light came on, and I got a loud tappety noise from the engine.
Checking it this morning, the tappety noise is still there - so loud you'd have to shout to make yourself heard with the bonnet open. Oil level is good, but the oil is as black as tar and I haven't changed it or the filter for ages (i.e. 2 years + ).

. No leakages from underneath, or from around the camcover gaskets.
I'm guessing that I've got a blockage in the oilways feeding the tappets / lifters - don't know the correct term - and a couple of oil and filter changes should do the trick. Perhaps some Wynns Lifter treatment too?
Any other suggestions? I did the aux belt / cambelt / breathers / water pump / camcover gaskets etc about 2 months / 500 miles ago, and I've got no error codes. The car has been sat outside the house with very little movement - maybe 200 or so miles in the last four weeks - because I've been quite ill.
Any suggestions would be appreciated.