1998 chrysler started overheating, then started making horrible grinding noise. Just bought this car a week ago. already replaced distributor cap, rotor cap and air filter b/c it was missing really bad. was told i need to replace converter...the plugs were fine. Any ideas?

Thanks for choosing FixYa Debra and welcome to FixYa. Chrysler is superior with electrical problems and failures. If it is still overheating, that may be the cause of the missing. Check the coolant level, hoses, and make sure coolant is in the radiator. The most common issue to overheating is a thermostat. This is after you have checked all the hoses and have checked for leaks. You could have internal engine damage from the overheating, such as a warped head or leaking head gasket. If it happened after the overheating, the overheating probably caused the problem. I believe the engine needs to be taken out and looked at. I know it is not what you want to hear, but it makes sense if the noise didn't start until the overheating. Now, it may also be an electrical issue cause Chrysler's are known for it. I would suggest testing the distributor wires/connections, look at the spark plug wires, anything to do with the ignition system.