1997 1.6 L engine knocking - bent rod?

[compcat]

My 1997 1.6L Corolla with about 180K miles developed a severe oil leak. I topped off the oil and was driving it to the shop. The oil light had not come on (not that low) when the engine developed a knocking sound. I immediately stopped & called for a tow. The shop has located & repaired the oil leak, but has only told me that a "rod is bent" and their specialized service technician will check it out today. Any ideas what I might expect? What questions should I ask? How much could various repairs run? I can't buy another car at this point. My finances are EXTREMELY limited. I need to make a cost effective, affordable choice. Any suggestions are welcome. I've been getting about 25 mpg, so compression is apparently good. While they are repairing the "bent rod" should I have them replace the timing belt as preventive maintenance? Would that save on labor costs, since they will already be opening the engine?

[Toyota Owners Club]

A bent conrod could only be caused by something like a hydraulic lock (water or other fluid in quantity between the piston and cylinder head) or similar which cannot be compressed and results in the rod becoming bent.

Alternatively, if the compressions are tested for each cylinder, the one with the bent rod will be lower.

Keep us update on the progress but bear in mind, if its a rattle its top end of the engine and if its a knock its bottom end and a bent rod would be a knock, not a rattle.

More than likely hydraulic tappets are weak due to loss of oil....suggest oil flush and change along with the filter once the oil leak is fixed.