Car is making a LOUD knocking noise

Send it to the salvage yard or head to the salvage yard to look for a replacement engine. Once the knocking noises start, there is a lot more worn than just the parts making that noise. It will need a total rebuild, and you can expect a remanufactured crankshaft will be needed. The rebuild will also address the original reason for losing the oil, but that will cost a lot more than a used engine. There should have been plenty of warning that something was wrong before the knocking started.

I bought a minivan that needed the same work although it wasn't run out of oil. Students did all the work but parts and machine shop work still cost over $300.00.