The car: 1995 Acura Integra LS hatchback 5spd stock w/ E / I The problem: When I started the car tonight it sounded like gravel was rolling around in the engine. The backstory: The car has 172,000 miles on it. I drove the car this afternoon with no problems. It has half a tank of gas, about 1000 miles since my last oil change, and good coolant/oil levels. Ideas???