I have a 95 Geo Prizm for my college son. It started making a funny noise - click, click, click only when it was moving. He took it to the local mechanic who said it was low on oil, if he'd put some oil in, the noise would go away, everything would be okay. Well, the noise got worse instead. He was driving on the highway, the noise got really bad, he started to pull over, there was a big thump, the engine died. So, how much does it cost to replace the engine, and could it possibly be worth it? The car's not worth much. But it's been reliable transportation up until now. Bought it 3 years ago with 80,000 miles on it. From my point of view, it's the cost of a replacement car vs the cost of the repair. Thoughts? Advice? Anyone have a really inexpensive car to sell me?