Replaced motor now making knocking noise

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. I'm sorry to hear you're having trouble with your F-150. A knocking noise coming from the lower part of the engine is often a sign of internal issues like rod or main bearing damage. Since the engine was replaced, there might be a problem with the new engine itself, such as improper bearing clearance or pre-existing wear. Low oil pressure or insufficient lubrication could also contribute. Double-check that the oil level and type are correct, and inspect for any signs of contamination or debris in the oil. Running the engine further could worsen the damage, so I recommend having it inspected as soon as possible. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!