Hyundai Repair: 2002 Sonata Knocking, sonata 2, realistic idea

Question
I have a 2002 Sonata 2.4 that I was going down the road at 55mph on cruise when the car lost alot of power and started knocking badly. I had the car towed home. It will start but it knocks, it has good oil pressure and no check engine lights ever come on. It sounds like the knock is coming from the top end but not definite. Do you have any idea what has happened? It has 100,364 miles and I bought it from a used car dealer and it only lasted 12 days before this happened. Any help would be greatly appreciated

Answer
If you've got a lack of power *and* a knocking, this sounds like a serious engine issue.  Without being able to hear the noise and listen to what things make the noise change strength and frequency, it's difficult for me to give you any sort of realistic idea as to the cause.  My first recommendation would be to take a long screwdriver and probe around to see where the noise is coming from.  But if the knocking is too severe, you could be doing additional damage just by continuing to run the engine.  If you haven't done so already, you should contact the dealer where you bought the car and see if they're willing to offer you any assistance.  There may be some sort of warranty on the vehicle, or you may have rights as a consumer because you've purchased it so recently.