1. Clunking or thumping can mean a defective universal joint, prop shaft or rear differential.
2. Heavy knocking or pounding from the engine/drive train can mean worn crankshaft bearings, bad connecting rods or loose bolts in the automatic gearbox torque converter.
3. Pinking or pinging can mean the fuel you are using is too low quality for your engine. This can be remedied easily by switching to a higher-octane fuel or having the ignition timing checked.
4. Metallic screeching or scraping can be a sign of worn brake pads.
5. Squealing can mean a loose fan belt or loose fan/air-conditioning compressor belt.
6. Thudding or thumping can mean a loose pulley or loose exhaust pipe.
7. A low-pitched rumble can mean wheel-bearing wear.
8. A ticking sound that increases in speed as the engine is revved can mean non-lubricated tappets due to low or dirty oil.
9. Whining can mean differential or transmission wear.