2001 Pontiac Grand Am - Randomly died, now runs?

I drive a 2001 Pontiac Grand Am sedan with 148k miles on it. It was a hand-me-down, but was taken care of well by the previous owner. It’s picky about starting, and requires you turn and hold the key just the right length of time, but is otherwise in good mechanical condition. A few weeks ago I was driving to the store when I came to a stop at a light. I turned right on red and during the middle of the turn, I heard a loud bang. I thought I had hit something, so I slowed down to pull over and check the car. The car slowed down faster than I was braking though, and when I hit the accelerator again I realized the car was only rolling, with no power from the engine. I came to a complete stop and turned everything off. When I looked, the body didn’t appear to have hit anything, and the tires were okay.

When I tried to restart the car, the engine didn’t turn at all and I heard was a very loud squealing, like a belt squealing sound. This happened for at least a dozen tries. I lifted the hood and everything looked normal, not that I have a clue. Finally I got back into the car after about fifteen or twenty minutes, and the engine started. I was able to drive it back home and park it. I haven’t driven the car anywhere else for fear of it dying again, but the engine has started right up every time I have tested it since this happened. Later I noticed a chunk of concrete broken off the curb, sitting in the street, that I may have driven over. I don’t know if it’s related. But otherwise I have no idea how or what happened. I haven’t been able to afford to take it to a mechanic yet.

Does anyone have an idea what might have happened?

Can you explain more about the requirement to “turn and hold the key just the right length of time” in order for the engine to start? What happens if you don’t turn and hold it just right? Is that still the case or has it changed since the stalling incident?

Also, did the car function normally during your drive home?

Was the broken concrete at the same intersection where the noise occurred?

It is pretty hard to say what happened. Perhaps a piston hit a valve. Check the oil for signs of coolant mixed with it. Also check the coolant level while the engine is cold.

Sometimes when you start it, the engine will turn but it won’t catch, and it will need two or three tries. You have to hold the key turned for a fraction of a second longer and then it will. From what I understand it has always been that way. It had the starter replaced a couple of years ago. When the engine is cold it always starts right up. That situation hasn’t changed since the stall.

The car was normal during the drive home. I did drive slowly with my hazard lights on, but I didn’t notice anything unusual. It isn’t making any weird noises now, and it’s started on the first try every time since the stall. The broken concrete was exactly where I turned. I could have driven over it, but I didn’t feel my tires roll over anything at the time and I didn’t feel an impact. I just heard the bang, and noticed the concrete later when I passed that area in another car.

I’m going to try to get it checked in a shop this week so I’ll ask them specifically about that, thank you.