Bobcat 873 duetz engine knock

[D.G.]

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

 

[D.G.]

Also the machine only has 950 hours on it if that matters any

 

[flyerdan]

Also the machine only has 950 hours on it if that matters any

With that few hours everything else should be pretty good, but I'd be concerned about how difficult it was to turn over initially. That could indicate that the bearing seized to the crank journal.
Since it did turn, it might not be damaged enough to need reground, only inspection will tell.
I had a Toyota once that broke a rod bolt and started hammering, I had another engine tore down and used the parts from it, and slathered the damaged journal with some soupy moly grease. It worked just fine for as long as I had it (several years), but it had nowhere near the forces that a diesel will generate on a crank journal.

 

[D.G.]

With that few hours everything else should be pretty good, but I'd be concerned about how difficult it was to turn over initially. That could indicate that the bearing seized to the crank journal.
Since it did turn, it might not be damaged enough to need reground, only inspection will tell.
I had a Toyota once that broke a rod bolt and started hammering, I had another engine tore down and used the parts from it, and slathered the damaged journal with some soupy moly grease. It worked just fine for as long as I had it (several years), but it had nowhere near the forces that a diesel will generate on a crank journal.

That's what I was hoping for. Im sure it got hot enough to swell the bearing and or journal to explain being hard to turn over initially. I've had small engines do that and then be completely fine after adding oil but like you said nowhere near the force of a diesel engine.

 

[foton]

That's what I was hoping for. Im sure it got hot enough to swell the bearing and or journal to explain being hard to turn over initially. I've had small engines do that and then be completely fine after adding oil but like you said nowhere near the force of a diesel engine.

I assume that you will be able to make that call when you pull the oil pan off, I would change mains and rod bearings at least. your call on what the crank looks like.