I hate everyone treating this like a vehicle issue; it's not. It's the owners fault for not taking a couple minutes to look at the manual and see what regular maintenance needs done at what odo reading. "Oh, the transmission fluid needed changed at 100,000km? How was I supposed to know!"
Owners manual.

Now that that's out of my system! Chances are your top end of your engine is gone. You'll have to replace it!

Best of luck.