A couple of weeks ago I started hearing what sounded like a loose piece of metal heat flashing making a knocking noise with the motor while accelerating. A few days later as I'm driving with my family in the car, we started losing power/torque to accelerate beyond 3500rpm, as we were driving on a highway on-ramp.

I pulled over, looked at the engine and everything seemed fine. I get back on the highway and have the same issue accelerating so I accelerate below 3k rpm. The knocking sound wasn't present at this time. As I'm getting near my house, the oil pressure indicator started to appear when I accelerated but disappeared within a few seconds. I get to my house and let the engine cool. When I check the oil, it turns out I've lost 2.4 quarts. I add oil and take the car for a short drive, only to find it wouldn't rev beyond 2800rpm without the engine clunking rather hard.

The next day I take it to my auto mechanic. He finds a crack in the upper half (2-piece) oil pan that is made of aluminum. He showed me that oil leaked on top of the plastic aerodynamic under body piece. Because my oil was leaking from this crack, the pressure was low enough to throw of 2 oil-regulators which accurately time the motor, thus likely warping the piston connecting rods.

After replacing the oil-regulators, which were damaged by the low oil pressure, the metal knocking noise didn't go away. There is likely crank shaft damage along with damage to the connecting rods. The mechanic doesn't want to rebuild half of the motor as he is certain the mechanics on the top end were slightly altered because of the damage on the bottom half.

Used motors vary in price from $2500-4500 and after labor I'm looking at roughly $4-7k total in costs. Thank God I bought an extended warranty.

After searching the internet, it looks like many many people are having the same problem I am, and at varying mileage.