2006 taurus won't start has a new battery and starter
The knocking is coming from the top of the engine
when I turn the key to crank it everything works so
why won't it start
From your description the starting system is working okay, but the motor is not running, and has a knock. That knock will have to investigated, it could be something serious (timing chain, crank, piston or rod bearings), to something slightly less serious (valvetrain noise). If you've replaced plugs and wires recently make sure the plugs are back on in the proper firing order.
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