This has happened 3 times in two weeks now. I have the ignition, but not the car on and am listening to the radio (NPR) and all the sudden the radio starts this loud “thump thump thump thump” and it only stops when I start the car. When I try to start the car it struggles and strains then finally catches. It’s a 1995 Chevy Lumina
Your battery is weak and is getting low. Also, make sure you turn the key to accessory and not to run. (If the check engine light is on while you are listening to the radio, you are doing it wrong. Turning the key to run instead of accessory takes a lot more power from the battery.) I’d replace the battery.
tardis is right. Also, your car is a republican and will stop punishing you if you just stop listening to NPR.