Thread watched MF231S Perkins 903.27 oil pressure fluctuations

[Dan S (NY)]

I have an MF231S with the Perkins 903.27 engine and after replacing a broken oil pressure light sensor I noticed the oil light has a faint flicker at all RPMs. I just recently got this tractor so I don't know the history but it only has 580 hours and runs really well. The oil and filter have just been changed (15w40 / Napa 1515). I temporarily installed a pressure gauge so I could see what kind of pressure I had and the needle is bouncing quite a bit. This is a relatively cheap gauge and probably has no damping but should it it bounding around like that? Below are two links to videos showing what it is doing. I only had it running about 5 minutes before taking these videos so its not warmed up, and when I have more time on another day I will see what it does and what the pressure drops to when warmed up more. I read someones speculation on a similair questoin that the oil pressure port is from the camshaft feed and may be pulsing as the camshaft rotates..don't know.

Another thing I am looking into is there a some air puffing back out of the air cleaner seal which increases with RPMs. I am thinking that no one has adjusted the valves since new and the intake may not be closing long enough and allowing a little blow back. At lease thats what I'm hoping. I will check the valves once I get the service book this week.
Any thoughts on these issues?

1200 rpm fluctuations

idle fluctuations

 

[Dieseltech]

I have an MF231S with the Perkins 903.27 engine and after replacing a broken oil pressure light sensor I noticed the oil light has a faint flicker at all RPMs. I just recently got this tractor so I don't know the history but it only has 580 hours and runs really well. The oil and filter have just been changed (15w40 / Napa 1515). I temporarily installed a pressure gauge so I could see what kind of pressure I had and the needle is bouncing quite a bit. This is a relatively cheap gauge and probably has no damping but should it it bounding around like that? Below are two links to videos showing what it is doing. I only had it running about 5 minutes before taking these videos so its not warmed up, and when I have more time on another day I will see what it does and what the pressure drops to when warmed up more. I read someones speculation on a similair questoin that the oil pressure port is from the camshaft feed and may be pulsing as the camshaft rotates..don't know.

Another thing I am looking into is there a some air puffing back out of the air cleaner seal which increases with RPMs. I am thinking that no one has adjusted the valves since new and the intake may not be closing long enough and allowing a little blow back. At lease thats what I'm hoping. I will check the valves once I get the service book this week.
Any thoughts on these issues?

1200 rpm fluctuations

idle fluctuations

Don't worry about the oil pressure gage needle moving, it's caused by the way Perkins supplies oil to engine top through one of the cam bearings as port is opened/closed as the cam turns. My MF 135 Perkins does the same thing. Any popping back at the intake is USUALLY caused by an EXHAUST valve not opening far enough to let the spent charge out. Broken/loose EXHAUST rocker will cause the charge to pop back when the INTAKE valve opens again. Have seen that happen on several engines in years past, Dad's MF 165 diesel did it all of a sudden years ago when one of the rocker arms broke.

 

[Dan S (NY)]

Thanks, that's a relief that the pressure gauge bouncing is normal. Hopefully once I adjust the valves that will fix the pop-back. The engine sounds good otherwise and started easily at 29 degrees.
It may be a week before I can get to it but I will post back with what I find with the valves.

Dan

 

[used red MN]

I suspect you know this means the flickering is an electrical problem. A spot in the wiring worn through contacting a ground is a likely cause. Not sure how complex the electrical system is on that thing, I would doubt very. I would try to run it with the oil light sender disconnected to see if the flicker is still there. Obviously per DT reply you don’t have an oil pressure problem.

 

[Dieseltech]

I suspect you know this means the flickering is an electrical problem. A spot in the wiring worn through contacting a ground is a likely cause. Not sure how complex the electrical system is on that thing, I would doubt very. I would try to run it with the oil light sender disconnected to see if the flicker is still there. Obviously per DT reply you don’t have an oil pressure problem.

Oil pressure light senders come in several pressure ranges, engine might have the wrong one as in too high range. A sender with 5/10 PSI would protect engine fine and stay lower than where the pressure fluctuates naturally.

 

[Dan S (NY)]

Oil pressure light senders come in several pressure ranges, engine might have the wrong one as in too high range. A sender with 5/10 PSI would protect engine fine and stay lower than where the pressure fluctuates naturally.

I may try and pressure test the sender I bought and see at what pressure it grounds the wire.

 

[Dan S (NY)]

Don't worry about the oil pressure gage needle moving, it's caused by the way Perkins supplies oil to engine top through one of the cam bearings as port is opened/closed as the cam turns. My MF 135 Perkins does the same thing. Any popping back at the intake is USUALLY caused by an EXHAUST valve not opening far enough to let the spent charge out. Broken/loose EXHAUST rocker will cause the charge to pop back when the INTAKE valve opens again. Have seen that happen on several engines in years past, Dad's MF 165 diesel did it all of a sudden years ago when one of the rocker arms broke.

Hey DT, I got sick the day after posting this message so I haven't been able to work on the tractor yet. While I'm asking questions, another issue showed up shortly after. It looks like the injection pump has started leaking out of what I think is the locking bolt. I am assuming this isn't something I would be able to fix myself and probably need to find a diesel shop somewhere that can overhaul this pump? Is this a common issue with these Perkins at less that 600 hours?

Seeing as I need to adjust the values I will have the cover off anyway so finding TDC should be easy then. I found the 903.27 Perkins manual online and it seems to have a good procedure on removing the pump. Anything special I should watch out for? Should I have a shop do a full rebuild while its off or can they just install some new seals?

Thanks,
Dan

 

[Dan S (NY)]

I suspect you know this means the flickering is an electrical problem. A spot in the wiring worn through contacting a ground is a likely cause. Not sure how complex the electrical system is on that thing, I would doubt very. I would try to run it with the oil light sender disconnected to see if the flicker is still there. Obviously per DT reply you don’t have an oil pressure problem.

The old oil pressure sensor was broken off and was hanging by the wire. The light never came on when it was like this. After watching the pressure gauge I installed in the block to check, I'm guessing the new sensor is set at to high a pressure and the bounce is dipping into the pressure sensor cut in point.

 

[Dieseltech]

Hey DT, I got sick the day after posting this message so I haven't been able to work on the tractor yet. While I'm asking questions, another issue showed up shortly after. It looks like the injection pump has started leaking out of what I think is the locking bolt. I am assuming this isn't something I would be able to fix myself and probably need to find a diesel shop somewhere that can overhaul this pump? Is this a common issue with these Perkins at less that 600 hours?

Seeing as I need to adjust the values I will have the cover off anyway so finding TDC should be easy then. I found the 903.27 Perkins manual online and it seems to have a good procedure on removing the pump. Anything special I should watch out for? Should I have a shop do a full rebuild while its off or can they just install some new seals?

Thanks,
Dan
View attachment 61890

That's the weep hole BETWEEN the two seals pump has that's leaking on the DP200 series pump. I can replace those seals IF the pump is removed CORRECTLY from engine. With the front drive gear cover off the drive hub U cutout is placed at six O clock position and located with a 5/16 inch drill bit through the hub U and into a drilled hole in the pump front. Then the gear to hub bolts removed as hub MUST stay on pump as it's NOT keyed to the drive shaft. The REAR seal is bad and why it leaks. I have the tools to remove/replace the drive hub, IF THE PUMP IS REMOVED FROM ENGINE CORRECTLY!! I don't have all the tools to go completely through that pump and have no desire at my age to ever get them, so seal replacement is ALL I'll do if needed. The shop I worked for it was common to see 1400/1700 bills against this model pump if the cam/scroll plates inside need replaced.

 

[Dan S (NY)]

That's the weep hole BETWEEN the two seals pump has that's leaking on the DP200 series pump. I can replace those seals IF the pump is removed CORRECTLY from engine. With the front drive gear cover off the drive hub U cutout is placed at six O clock position and located with a 5/16 inch drill bit through the hub U and into a drilled hole in the pump front. Then the gear to hub bolts removed as hub MUST stay on pump as it's NOT keyed to the drive shaft. The REAR seal is bad and why it leaks. I have the tools to remove/replace the drive hub, IF THE PUMP IS REMOVED FROM ENGINE CORRECTLY!! I don't have all the tools to go completely through that pump and have no desire at my age to ever get them, so seal replacement is ALL I'll do if needed. The shop I worked for it was common to see 1400/1700 bills against this model pump if the cam/scroll plates inside need replaced.

I will work on removing the pump correctly and hope it doesn't need a $1700 rebuild. It starts and runs great so hopefully its just some tired seals. Looking for a place this week I can take it to in person as I don't really want to ship this. Looking at the Perkins manual it shows two different Delphi pumps: A 'pin timed' pump which sounds like what you describe, and a 'locked' pump that has a locking bolt on the side and the drive gear is on a keyed tapered shaft. I think I have the 'locked' pump. Hopefully once fixed it will last at least another 500-600 hours.

 

[Dieseltech]

I will work on removing the pump correctly and hope it doesn't need a $1700 rebuild. It starts and runs great so hopefully its just some tired seals. Looking for a place this week I can take it to in person as I don't really want to ship this. Looking at the Perkins manual it shows two different Delphi pumps: A 'pin timed' pump which sounds like what you describe, and a 'locked' pump that has a locking bolt on the side and the drive gear is on a keyed tapered shaft. I think I have the 'locked' pump. Hopefully once fixed it will last at least another 500-600 hours.

The pinned hub with the U slot in hub has the lock time bolt too...

 

[Dan S (NY)]

The pinned hub with the U slot in hub has the lock time bolt too...

Ok, thanks, I will look for it.