L3410D tractor low engine oil pressure warning

[robferry]

I have an oil pressure warning light coming on when the engine hits about 1500 rpm. Below that it's fine. I haven't attempted to tackle the problem yet. Has anyone had a similar experience??

Rob

 

[Roadworthy]

It sounds like a defective oil pressure sensor. You can confirm this by temporarily installing an oil pressure gauge in its place.

 

[robferry]

It sounds like a defective oil pressure sensor. You can confirm this by temporarily installing an oil pressure gauge in its place.

I checked oil pressure mechanically, it's all good. I'll replace the sensor when I get a chance. Thanks for your help,

Rob

 

[lugbolt]

what is your oil pressure when checked with mechanical gauge?

I have also seen some wiring issues cause similar complaint

 

[robferry]

what is your oil pressure when checked with mechanical gauge?

I have also seen some wiring issues cause similar complaint

My gauge wasn't great but the readings were less than ten psi at idle (700 rpm) and around 30 psi at 2700 rpm. There could well be wiring issues but I need the tractor for moving snow, we've had an absolute ton. In the short term I plan on installing a mechanical gauge so I can keep an eye on things.

Cheers - Rob

 

[GeoHorn]

My gauge wasn't great but the readings were less than ten psi at idle (700 rpm) and around 30 psi at 2700 rpm. There could well be wiring issues but I need the tractor for moving snow, we've had an absolute ton. In the short term I plan on installing a mechanical gauge so I can keep an eye on things.

Cheers - Rob

Oil pressure importance is closely tied to oil temperature. What is the oil temp when idling at 10 psi? (And high oil temps might indicate a combination of blocked cooling system and piston-ring blow-by.... Does the crankcase breather have indications of excessive exhaust-pressures at operating RPMs?... place a hand a few inches from it and see if you feel hot gases and/or oil misting.)
A simple method to determine oil temp is with a long BBQ thermometer (sold at Academy etc) for about $5. Stick it in boiling water to confirm it is accurate at around 210-F. Then, stick it down thru the dipstick-tube into the crankcase oil. This can be done either running or stopped.
At idle, many worn engines will display “low” oil pressure...but anything above 5-psi is adequate at idle. Hopefully you’ll have 20-psi or more at PTO-operating speeds.

FYI-The most common cause of low oil pressure at operating RPMs is worn main bearings. But do not fall for a belief that just because low oil press at idle on a hot engine is cause for tear-down of a high-time engine.... because it‘s merely confirmation of what we already know, ... and if the oil press and temp is within operable-range at working RPMs then the engine is doing it’s job and performing as expected.... Put it to work. (This is also a good reminder of how instrumentation is superior to idiot lights.)

 

[robferry]

Oil pressure importance is closely tied to oil temperature. What is the oil temp when idling at 10 psi? (And high oil temps might indicate a combination of blocked cooling system and piston-ring blow-by.... Does the crankcase breather have indications of excessive exhaust-pressures at operating RPMs?... place a hand a few inches from it and see if you feel hot gases and/or oil misting.)
A simple method to determine oil temp is with a long BBQ thermometer (sold at Academy etc) for about $5. Stick it in boiling water to confirm it is accurate at around 210-F. Then, stick it down thru the dipstick-tube into the crankcase oil. This can be done either running or stopped.
At idle, many worn engines will display “low” oil pressure...but anything above 5-psi is adequate at idle. Hopefully you’ll have 20-psi or more at PTO-operating speeds.

FYI-The most common cause of low oil pressure at operating RPMs is worn main bearings. But do not fall for a belief that just because low oil press at idle on a hot engine is cause for tear-down of a high-time engine.... because it‘s merely confirmation of what we already know, ... and if the oil press and temp is within operable-range at working RPMs then the engine is doing it’s job and performing as expected.... Put it to work. (This is also a good reminder of how instrumentation is superior to idiot lights.)

Thanks for the great feedback, I guess once I've installed a manual gauge, I'll know the oil pressure under all operating conditions (pto etc).

I get your point about oil pressure and oil temperature, I'll try to get a thermometer to check it. Question for you : what should ideal oil temperature be?

I must admit before, I manually checked the oil pressure I was really worried I might have to tear the engine down (expensive even if you do it yourself)

The tractor is 20 years old but only has 1000 hours, so it should not be worn out. However, as you may have noticed I live in Canada and winter conditions are sometimes brutal. I have often started it at minus 25 deg C (minus 12 deg F). I use Rotella T6 synthetic oil which allows me to get away with that but I'm sure starting in those conditions is really bad for it and I"m worried I may have damaged rings etc. Is there a simple way I can check blowby or compression on a diesel.

Thanks again for your help. Rob

 

[GeoHorn]

OIl rapidly oxidizes at temps above 240-F. Anything below 220-F is acceptable, below 200-F is good, but above 160 is necessary to drive-away moisture from combustion by-products. (a good reason to retain a thermostat in the cooling system for those operating in warmer climes.)