Engine knocking on 1999 Ford Expedition

i juss got a 99 expedition 4 free wit 280000 i was driving it and started knocking wen i look it had no oil ...how much is it to fix it or how much is it to put a new engine... and is it too hard to do it myself to???

1 answer
Hello, did you need to replace your engine to fix the knocking noise, or was it repairable?