Engine Problems, Please Help

[Richie (Paseo)]

Right, I will try and describe this the best that I can. I am having engine problems. The engine is tapping really badly, the higher the revs go the faster the tapping gets. But it comes and goes, can go a week or 2 without hearing it then it comes back worse than ever. I was told it was more than likely to be one of the oil lines were blocked , so the cams werent getting enough oil and were banging up and down. So i got some engine flush and flushed it through and changed the oil twice, but it is still there. But I have found that if I accelerate hard and bounch the revs off the red line a few times it seems to stop tapping, sometimes for days!

I took it to a garage just down the road from me, and the said they havent got a clue what it could be.

Any idea what it could be?

Does it sound serious? If it is I will prob do the 4e-fte swap.

Is it likely to break down? ive got to drive up north next week.

Any help would be GREATLY appreciated

Thanks

Richard