Sorry to say but the knocking sound is the most worrying bit. It sounds like a bearing or internal engine component has failed. Your mechanic will be the best person to advise you, but it will probably mean at least an engine strip down which will mean the head gasket will have to be replaced if the engine is economically repairable. Something similar happened to me, years ago and I had to replace the engine. (I got a second hand one from an accident damaged car as the faulty engine could not be economically repaired).

You don't need to worry about a blown head gasket. You pumped all of the engine oil out of the engine and it was unable to internally lubricate the engine. Replacing the head gasket will only be a small required part of replacing the engine.

Head is probably OK. Sounds like you threw a rod. New engine time!

if the oil light came on and it was over heating,i think you need a new engine.

sounds like internal engine problem but any answer i give is just a guess

Was driving on the highway last night - suddenly check oil light comes car is overheating and hearing a knocking sound under the hood. Managed to pull over immediately - white smoke started coming from the hood - went away after 5 minutes. Tried starting car up - sputtering sound. left it alone. had it towed to my mechanic. Once we got their noticed the car was leaking a lot of brown oil.

I prey to GOD the head gasket is not blown - it wouldn't be worth the 3K in repairs. Hoping its just a leak or radiator malfunction.

If anyone has experienced this or knows about cars better than me please help! First time having this problem car has been well maintained up to this point.

Thank you!