L2250 low oil pressure

[Mad Mike]

So over the last few weeks the oil pressure light started to stay on for a second or two after starting and I didn't think anything of it.

Last week I bogged her down and then the light started to flicker at idle. Now she sometimes flickers at idle and minimal idle increases, sometimes she doesn't. I changed the filter and oil (10w 30 standard) thought it was fixed but it came back today (for a little while) I'm thinking (hoping) its the sending unit. I do see other things mentioned on this site like the check valve, pickup tube and O-ring (most likely to me would be the check valve. I guess I'll start with a mechanical gauge as a check and pray its just a failing pressure gauge, unless someone has other suggestions...

 

[85Hokie]

Mike,

Welcome to the forum!

Did the light still flicker when the engine gets good and hot?

A cold engine - the psi is up there, way up there - like 50-60 psi - as the oil gets hot it thins and PSI drop, and sometimes drop a lot.

I think for the few bucks - I would replace the sending unit. If you want to go the extra mile, get a mechanical gauge and get a good idea what the psi is over the entire RPM range.

 

[Flintknapper]

I'd go straight to the mechanical gauge. Best to KNOW right now if there is an issue (actual low pressure) or not. IF you have good pressure...then yes, replace sending unit and go from there.

As @85Hokie already stated.....oil pressure should be highest (at idle speed) when the engine is first started and the oil has yet to warm. So if ever you were going to have good oil pressure....it would be then.

Any light/meter/reading suggesting otherwise would have me concerned.

 

[Mad Mike]

Thanks gents for confirming my train of thought I'm hoping for the best. Have a Oil pressure gauge and just picked up adapters to fit the tractor. I am not looking forward to a self rebuild and don't know of anybody in North Idaho that even want's to touch anything older than 5 years anymore.

 

[North Idaho Wolfman]

That engine is not really know to have issues, so I'd bet it's just a bad sensor.
Throw a mechanical gauge on it and you'll know.

 

[Mad Mike]

Mike,

Welcome to the forum!

Did the light still flicker when the engine gets good and hot?

A cold engine - the psi is up there, way up there - like 50-60 psi - as the oil gets hot it thins and PSI drop, and sometimes drop a lot.

I think for the few bucks - I would replace the sending unit. If you want to go the extra mile, get a mechanical gauge and get a good idea what the psi is over the entire RPM range.

Today, yes, it didn't flicker until it got warm, I wouldn't say it got good and hot because I was really only idling her and it got into the mid 40's here tops. Everyone is on the same page - hook a gauge to it and see, which is really about the only thing you can do...

 

[Mad Mike]

That engine is not really know to have issues, so I'd bet it's just a bad sensor.
Throw a mechanical gauge on it and you'll know.

NI Wolfman, I'll be on that tomorrow... I do hope its just as you say...

 

[Mad Mike]

Does anybody know what the RIGHT threads are for the sending unit? I can't seem to get the right adapters...

 

[North Idaho Wolfman]

1/8" BSPT if I remember right.
For testing purposes you can get a 1/8" NPT to fit in a couple of thread turns, which is enough for a quick test.

 

[85Hokie]

Double up on NIW - they should be 1/8 BSPT - which is a bit hard to come by at the local hardware store.
NPT threads are very close but - not a good idea for a permanent solutions.

Here is a solution - will work unless it sticks out too far :

https://www.amazon.com/GlowShift-Fe...462071&sprefix=1/8+bspt+to+npt,aps,228&sr=8-1

 

[TheOldHokie]

Does anybody know what the RIGHT threads are for the sending unit? I can't seem to get the right adapters...

Online. Whats the thread on your gauge?

Dan

 

[Flintknapper]

Here is a solution - will work unless it sticks out too far :

^^^^

When I added a digital oil pressure gauge to my Land Cruiser, I ran into that problem.

Block was BSPT and sensor was 1/8" NPT. Could have used an adapter but it would have ended up sticking out too far from the block.

So I just re-tapped the block 1/8' NPT. Easy to do.

 

[007kubotaguy]

To check the oil pressure you will need a 1/8 British pipe adapter to your gauge. Standard pipe just won't start in the hole. On larger pipe sizes it's no problem. I've tried to use 1/8" npt and it won't work. Most Auto Parts stores will have them.

 

[GeoHorn]

$8 … Brass. (Brass is good, self-sealing, and easy on the block threads.)

https://www.amazon.com/CDQBWKJGFJ-BSPT-NPT-Adapter-Fitting/dp/B0CMTLJ1M2/ref=sr_1_5?crid=1MUQRF7UM8EDN&dib=eyJ2IjoiMSJ9.Lufpk0VL3HSZCaKuMCOLi_3vFDH_mtIbP43e92NwGr3ChuzRv2-VXObJ3GUWVg1MC5wegqD5mkNHFsxIhjeOUAlyqC8m2HZhZid_piMY28wcuvQkM6sz5uKfcngGb7Fhn5k84Ljz3FVlseK0XnD0ZfE_T9A8ZmVGDq6kNvhJJfUROPPM3k_SlEZ4xDYB08a2cS-2tHVO6MZs7Jb3qLncETFlY9RVnaf043obBjFpwUs.LVdsPzJ_t-iqkWBhn3s1CSjJp-k_E_pRuB5LAZVHJiU&dib_tag=se&keywords=1%2F8%2Bbspt%2Bto%2B1%2F8%2Bnpt%2Bstainless&qid=1708515796&sprefix=1%2F8%22%2Bbspt%2Bto%2B%2Caps%2C144&sr=8-5&th=1

OR….if you plan to keep your idiot-light also…. This adaptor is 1/8 BSPT to 1/8 BSPT ..AND… 1/8 NPT.

https://www.amazon.com/dp/B08LQN61K6/ref=sspa_dk_detail_0?pd_rd_i=B08LQN61K6&pd_rd_w=XLTaZ&content-id=amzn1.sym.386c274b-4bfe-4421-9052-a1a56db557ab&pf_rd_p=386c274b-4bfe-4421-9052-a1a56db557ab&pf_rd_r=59JZCWKG2BWMZHQZ7FJ0&pd_rd_wg=cvcAQ&pd_rd_r=ab88d986-dc12-4614-927f-48013d0353b4&s=hi&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&th=1

 

[GreensvilleJay]

gee, I looked online, oil pressure sensor is $11 US, Buy it, replace it.
looks like typical sensor/switch. inside there's a rubber barrier between oil and switch contacts.over years of starts, rubber fails.nature of the beast. In certain Fords, it allows power to ignite oil,then oopsy...no more Ford.
if you decide a gauge would be better,install a Tee AND replace the OEM sensor. it 'might' also feed a 'computer'

 

[Mad Mike]

All. Awesome forum here! All good suggestions and great answers. Ended up doing a T from Amazon with both BSPT male and female and a NPT female (Like Geohorn had mentioned) for the gauge (had on hand),Still had to do an elbow (also had on hand) for the sending unit (And I had already ordered that) All parts had shown up by today. got everything installed and tested. Cold idle pressure 65lbs, warm idle pressure - Well I couldn't get it to drop below 45 lbs - So I would say I am safe.

BUT - I did discover a new issue, cracked exhaust manifold ear, CENTER cylinder. As I don't think welding cast is all that feasible, does ANYBODY know where I can go looking for a replacement?

 

[TheOldHokie]

BUT - I did discover a new issue, cracked exhaust manifold ear, CENTER cylinder. As I don't think welding cast is all that feasible, does ANYBODY know where I can go looking for a replacement?

Your exhaust manifold is still available from Kubota. Messicks says they have one in stock - $275 plus shipping and tax

Kubota #17325-12312 MANIFOLD, EXHAUS

MANIFOLD, EXHAUS

www.messicks.com

Dan

 

[GreensvilleJay]

You can have it BRAZED and it'll hold for a few decades. Easy enough to do.

 

[Russell King]

Contact @007kubotaguy
He has used parts for some older tractors.