I have a 1993 2.3L DOHC Grand Am that broke down today. The oil pressure seemed to be a little lower(15psi) than normal but never dipped into the red warning area. I think normally it would run at about 25psi. I was driving on the highway and I started to hear a terrible noise that sounding like rocks inside the engine. So I pulled over and the engine stalled. Do you think the oil pump went bad in the engine? Do you think the engine is shot? Need some advice. Thanks.

sounds like the oil pump or timing chain went. In both cases, the motor is toast.