I recently bought a 05 mazda 6 with the 4 cylinder 2.3 L. This motor has the separate coil pack mounted to the driver side of the motor. It has severe rod knock, so my first plan of attack was to get another 2.3 motor from the junk yard and swap it out. They are telling me that the ONLY motor I can replace it with is a 05 2.3 L, the EXACT motor I have. I am questioning if this is correct or not? They have a few 2.3 L engines there and they look identical. The vehicle year is different, but motor visually looks the same. There is also a couple 2.3s with the coils on the spark plug wires. If I am just replacing mechanical parts, the head and block, or maybe a crankshaft if necessary, wouldn't any 4 cylinder 2.3L motor/block/head from a certain range of years work? Or also the Ford Fusion 2.3L. Thank you for your help! They aren't making sense to me, and I'm not sure I believe them, but want more advice before I spend the money on something that won't work.