Car stalls and knocks after repair

2002 ford ranger. Truck was running rough. I did a oil change and changed out the spark plugs and air filter. Wires are only about 2 years old. Car still ran rough so it sat until I could afford to get it to a mechanic. The mechanic replaced the fuel pump and filter and the cyl 1 coil. Got the car back and it ran for 2 days and then died on me while I was driving down the street. When I attempted to restart it there was a knock that sounded like someone knocking on a shower stall wall and died. On the third attempt I was able to get the truck home (thankfully I had just left the house and was only at the end of the street). I called the mechanic back and was told that he thought the oil pan needed to be cleaned because gunk that was in the oil filter had dripped back down into the tray and when I drove the car it got sucked back up into the oil filter and clogged it starving the engine for oil. I spoke to another mechanic who has never heard of this any other ideas?