Where to get a new engine?

Not sure if this is the right place but seems as good as any.
So last night I was driving my car coming back from dinner and the engine started knocking. The oil pressure light has been dancing on and off for couple days now, thought it was just a fluke thing, hit a bump funny or something. Turns out I was at least 3 quarts low on oil. It was suggested that I should just buy a new engine and swap them out. I live in Chicago land and have no clue where top find a running motor with relatively decent miles for a fair, preferably cheap, price-tag. My current motor has 168k on her so I was hoping to get something less than that probably closer to 100k at least so parts don't start breaking on the new one.

Im sure most people will tell you a junk yard. What you could also do is look on other forums(Mitsubishi) and see if there any postings.

my dad ran my motor with no oil on the dipstick for like 2 weeks. nothing happend to my motor.

does the car still run?

I wouldn't replace the whole motor for this problem. I remember my moms old Sebring had a major oil leak, it would go from 5 qrts to nothing in a week. I wasn't around one particular week and the engine seized. Added oil ANC got it to start, the thing tick for a day straight. Afterwards it was fine.

thats what i'm saying. my car burns over 3 quarts a month. still runs decent tho.

The car still runs, yeah, but not sure how well above 3k rpms, don't want to have it accidentally slip up there and break more than it already has..what if I spun a rod bearing? still OK to drive?

Just drove it and it knocks at any rpm over 1500, not audible at idle

I think you will not find the engine in good condition. The best option overhaul of your engine. You will be 100%sure. Boring, crankshaft, inserts with repair size. Pistons and rings repair size. The oil pump new. Replacement of all gaskets and seals. It's cheaper than an unknown engine. IMHO

If you just need a cheap low mileage motor just get a jdm 4g63 sohc.

My favorite place to shop for replacement parts from junkyards is http://www.car-part.com/ I like it because you can have it sort by price or distance from you

Sounds like you spun a bearing. Drain your oil...if it has metal fragments or a metal tint of color, its a spun rod bearing.

Dropped the oil pan, and yeah, there was a ton of metal fragments, like more than i ever thought possible. one of the bearings was gouged and scored really bad, even became very out of round, the other ones were also scored and a bit gouged but nothing like the one that was knocking.

I replaced the connecting rod bearings with new ones and the engine runs fine now, not sure how badly beat up everything else in the engine got because of that (connecting rods etc), the crankshaft didn't look to be badly damaged at all so I guess I got lucky there. Thanks for all your help everyone!