2003 Holden Commodore • 155,000 miles

The car hadn't been started for months.
I started it and there was a loud tappet noise which went away within 15 seconds.
This happened 2 days in a row, but the 3rd day the tappet noise did not go away.
I noticed after this that the oil was a little low ( at the "add" level) but not empty and it is around due for an oil change but not far over.
Could anyone tell me what could possibly be happening? And can the lifters be silenced again without having to pull the engine apart?
I have filled the engine with fresh oil, but lifters noise still exactly the same.
Black VY
April 22, 2012.

You can try an engine flush or one of the lifter free up additives, but this may not work, fair chance that the lifters will have to be replaced, trying the additives for this problem will not cause any harm.

Apr 22, 2012.