Hello. I purchased a bobcat 873 with the duetz bf4m1101f engine from a neighbor. It developed an oil leak and he didn't keep an eye on the oil level and ran it low. It started knocking and he said he shut it off. Tried to start it back up and engine would barely turn over. Couple weeks later I went down and filled it with oil ( almost 3 gallons). It fired right up and sounded good for about 30 seconds then the knock started. I haven't ran it long enough to get up to operating temperature but the knock is noticable especially in higher rpms. Using a screwdriver I can hear the knock most prominent around the first and second cylinder just above the oil pan. Otherwise it runs good and engine sounds good. I've been a mechanic for many years but not a whole lot of experience with diesel engines. I'm thinking it spun a rod bearing but wonder if there is anything else it could be. And can I get away with repair/replace whatever is needed for the bearings and be good? Im just gonna use it around my property. Thank you