Engine ticking, oil light flicker??

After fixing the problem with the regulator and alternator in my EA, I have developed another issue.

Went for long, hilly drive on weekend, temp gauge higher than usual and oil light began to flicker.

I could feel vibration through the accelerator pedal, so I pulled to side of road.

Engine was very hot, and there was a ticking/tapping sound from the rear of the engine (Under the cover thingy on the side of the engine, not actually in the engine block).

$120 tow to get the fu#@er home (That's with RAA Plus - ha, what's the point)

Waited 24 hours for engine to cool and checked the water - all fine and full.

Checked the oil - seemed lower but no leak anywhere. Topped oil up and started car.

OIl light not on at first, tapping sound only present for a few minutes.

Took car around block - no worried.

Back to driveway, turned car off then on again, oil light back to flickering - til I put my foot down. Tapping sound only quiet til I put my foot down also.

What's the problem now????? And is there anyone in S.A who could come and look at it for me???