MF 250 Oil pressure low and squealing/knocking

[FoggyB]

Hello, I was out spreading manure today and noticed that oil light came on on my MF 250 - initially thought it was because I'd just gone across a steep side hill and oil level was a bit low. But oil light stayed on on the level and within 30 seconds noticed slight engine knocking noise.

Shut down, checked and topped up oil - restarted but still squealing and knocking - oil light still on, immediately shut down and towed home
Question - were should I start my investigations? Or does someone have the likely diagnosis from these symptoms? Many thanks....
 

[samn40]

Looks like your oil level was too low for too long! I think you need to at least drop the sump and check your shell bearings for scoring.You may have to remove and regrind the crankshaft. Do not be tempted to start the engine until you have found the problem. It is common enough to have the bearing seize and snap the endcap bolts and then stick the conrod out through the side of the block, commonly called 'sticking a leg outta bed!!'
Good luck...Sam
 

[DavidP, South Wales]

Hi,
To add to Sam's comments the removal of the sump is the first step. On the 250 you will need to remove the front axle casting first to clear the stud. Check the suction pipe from the strainer to the pump. Later tractors had a rubber grommet to hold the pipe but there should be no problem there. Slide each con-rod on the crank in its play. I suspect that number 3 will be faulty as it is the furthest from the oil pump and normally suffers first.
DavidP, South Wales