reconmike

when subarus run low on oil the lifters rap to high hell, fill it with oil and bring it just above idle, the noise should dissapate some.
If it does quiet down all you might need is a timing belt and some seals.
if your car isnt smoking blue smoke out the tail pipe then it has a leak.

I would bet it is coming from the front crank seal, a very common problem with subaru.

It is very hard to get one to knock.

let us know how you made out.

Edit....you should be able to drive it with out launching a rod and killing your car.....just take it nice and easy.

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