Engine Knocking

I have a 2006 Chevy Impala, 114K miles, never been wrecked, recent oil change, everything seemed to be working fine. Today while I was driving I heard a real loud knocking noise coming from my engine, I pulled over, turned the car off, and popped the hood. (Not sure why because I know jack shit about cars lol). The knocking stopped when I turned off the car, so I waited about 5 minutes and tried to turn it on again.The car wouldn’t start so I had to get a jump. After that, I drove around the parking lot, then turned the car off and on again, and repeated that several times, but no knocking ever came back, and everything seemed fine. Anyone know what it could be?

Huh?. Knocking usually means “You need a new engine” or “Stand back she’s gonna blow!” It very nearly never goes away allowing the engine to continue. Why did you have to get a jump? Was the battery dead? Did any warning lights on the dash come on? Red ones? yellow ones? anything?

Perhaps you mean “pre-ignition knocking” or pinging?
although that would not be considered loud.

Did you check the fluid levels (oil, coolant, trans) while the hood was up?

Is this the first time the car wouldn’t start right up after turning the engine off for a brief time? Did you crank it many times trying to get it to start, and that ran the battery down, is that the reason you needed a jump? The reason I ask is b/c it is unusual to need a jump start when you’ve only recently turned the engine off. Even a battery on the decline will usually crank the engine easily in that situation.

I’d recommend that the first thing you do is get the owner’s manual out, read it thoroughly, check all your fluids (especially your oil) per the manual, and let us know what you find. Do not assume that because the oil was just changed it’s fine.