As soon as I turned left onto the road to head back home from work, the engine on my 91 Accord (270K++ miles) just freaks out and starts making this HORRIBLE, LOUD sound. I pull over and turn off the car.

I tried starting up the car and no response..I opened the hood and wiggle the connections to the battery (i need to tighten them) and after that..my car turns on..but as soon as I turn it on..it just has a REALLY LOUD, annoying, machine-gun-like noise coming from somewhere in the engine.

I really hope it's something minor, but from what it seems...it might not be. Any input would be greatly appreciated.

Thanks!