# Diagnosis help??



## cccc (Mar 28, 2012)

Not a tractor expert at all - just a decent shade tree mechanic. An unusual situation has arisen and, if possible, I'd like some expert insight before proceeding. 

Wife was mowing brush our MF 230 gas tractor with rotary attachment and noticed engine slowing down and temp rising to red zone, so she disengaged the pto and brought it in to the garage. 

I checked oil, coolant system, etc. and found no issues. Started the tractor to check fan operation and heard a squeaking noise when engine turned over. It started fine and usual engine/exhaust noise would have covered any such squeak while running - BUT IMMEDIATELY NOTICED THAT THERE WAS ZERO OIL PRESSURE. Wife has been very good at monitoring gauge levels but said she had not noticed the zero oil pressure after the engine slowing and heat issues started.

I let it sit overnight and this AM it started fine with minimal sqeak when turning over, but still no oil pressure - shut it down right away. I have thought about disconnecting the tube to the oil pressure gauge to see if there is pressure but bad guage function, but hate to run the engine with doubtful oil pressure.

Might these symptoms indicate a failed oil pump and, if so, how to further diagnose and repair?? Would such failure bring about the "squeak", or am I possibly hearing a dry bearing? (No knocking noise from engine so far)

If I can determine that the oil pressure gauge simply has quit, might the engine slowing and temp rising be due to excessive drag caused by problems with the rotary mower attachment?

What would you experienced people do at this point? Thanks for any help.


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## BigT (Sep 15, 2014)

Hello cccc,

Welcome to the tractor forum.

You have several symptoms of zero oil pressure: 1) Engine overheating, 2) Engine rpm slowing down, 3) Bearing squealing, 4) Oil pressure gauge reads zero. 

I would pull/drop the oil pan and check on the oil pump for dropped pickup tube, broken shaft, relief valve stuck open, etc. While you are in there, you might want to check the rod and main bearings.


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## cccc (Mar 28, 2012)

Thanks for the quick repky Big T. Your synopsis is helpful - if it is oil pump failure, hope any resulting damage is not serious, It's just a fixit project I do not need right now.

Any other thoughts/suggestions out there?


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## FredM (Nov 18, 2015)

cccc said:


> Thanks for the quick repky Big T. Your synopsis is helpful - if it is oil pump failure, hope any resulting damage is not serious, It's just a fixit project I do not need right now.
> 
> Any other thoughts/suggestions out there?


I agree with BigT, there is a good possibility that a main bearing or big end bearing has grabbed their respective crankshaft journal and spun in its housing, for your sake, I hope not.

You will have to drop the sump no matter what.


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## cccc (Mar 28, 2012)

Thanks to BigT and FredM for the replies. Still looking for savvy insight.

Dropped the oil pan and initial inspection shows that bottoms of pistons, bearing housings, camshaft, etc, are wet with oil, and the oil pump pickup can and delivery tube are intact and seemingly in place. 

Before I start taking more stuff apart, am wondering if I should run a test on the oil pressure gauge to see if it just quit. Looks like there is no way to test the oil pump without removing it. (Anyone know a way to do so?) The drive gear for the pump has a bit of roughness on some teeth and a small amount of lash with the cam gear.

In the bottom of the sump I found a few very small pieces that go to magnet, some specks that seem not attracted to the magnet, and then a strange piece of a larger part as pictured below (size is about 1" by 2"). I cannot identify it and cannot find a place up in the bottom guts where it might have broken off. Can anyone tell me what this is from and its normal location? Would its breakage have led to zero oil pressure?

As ever, thanks for any help before I begin further dis-assembly.










[/ATTACH]


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## sixbales (May 18, 2011)

Yes, pressure test the gauge and sending unit if possible.

I would expect that you would find components externally wet with oil. The crank should be splashing some oil, even if the pump wasn't working. 

Ask a Massey Ferguson mechanic if he recognizes the piece you found in the pan. Looks to me like part of a light duty spacer of some sort.

Does the pump rotate when you crank the engine (make sure that engine won't start)? Have you checked the relief valve for stuck open? Need a manual before fooling with the relief valve.


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## cccc (Mar 28, 2012)

Thanks sixbales. I have the manual, so will check as you indicate. Need to learn about that relief valve, and need to figure out how to check pump output while it is in there - even if drive gear turns the pump may be faulty somewhere internally. This thing is going to be "down" for a spell.
Thanks again.


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