Low Oil Pressure

I purchased my '53 Jubilee from my sister and have recently been working on it. I got it running pretty well and used it for the first time with a 5' brush hog. I'm running 15W - 40 Rotella oil with a wix spin on filter kit. I noticed the oil pressure seemed very low compared to what I thought it should be. I'm running about 25 psi with hot oil at around 1500 RPM. At idle, about 5 psi. When the engine is cold, runs about 39 psi and around 15 psi. Is this somewhat typical for an older girl? runs fine, has fair amount of blow-by, not the best compression...unless I add oil to the rings. Unit only shows 495 clock hours. Any thoughts? Should I rebuild the oil pump? Just run it and enjoy it? Immediately stop using it? etc.

With what it's showing I doubt it will ever give you a problem. Or you can replace the crank bearings, along with the cam bearings. Then while you are at it you can rebore it. I would just leave it alone. You need to remember you are dealing with a tractor that is probably older than you. Stan

Sound about right for a 65 year old tractor and is very common

Well The hours are more than likely not correct. Those tachometers just did not last long so it would be really rare for it to be the original. Also a 66 year old tractor only having 495 hours would make the tractor very valuable and in pristine condition not losing oil pressure when running at operating temperature.

The oil pressure your seeing is inline with a worn Ford motor of that vintage. With cam shaft driven oil pumps you see more of a difference between low and high RPMs. This is one reason most modern engines have crankshaft driven oil pumps.

Also I am not a big fan of multi grade oils in older motors. Especially ones with wear. I would try some straight 30 weight oil in the motor and see what that does. Now this is for summer usage. For winter go to a 10w30 oil. A 15w40 oils is more a diesel engine oil.

These old Ford motors where not long life motors. When farmers around here where using them hard, they would overhaul the motors every 3-4 years. An overhaul kit did not cost much and usually the crankshaft would be fine. Most farmers could do the majority of the work themselves. The trouble was most of these tractor only got inframe overhauls unless the rear seal was leaking. So the cam bearings were rarely changed. Motors with the type of oils system your tractor has you could very well have worn cam bearings causing the lose of oil pressure.

So change the oil from a multi grade one and run it unless you want to spend the money to overhaul it. To do it right could easily be $1500-2000 with machining and little outside labor. If you hire it totally done it easily could be $2000-2500.

Thanks, Yes, it's older than me. I was thinking the same thing, but wanted to bounce it off a few others. I hear no knocking and it runs solid, no skips, ticks (after resetting backlash) etc. Thanks!

Thanks for the advice on the oil. I wasn't sure about the 15W-40 and new it was for a diesel. I will do exactly as you suggested and keep you posted. Good info. on the cam driven oil pump etc.

That is sufficient oil pressure for that engine.

The 15w40 diesel oil is the most common replacement oil for single grade oil. You can run single grade if you like, SAE 30 or 40. But the multi grade will give easier cold starts, especially if it's still 6 volt.

The reason for running diesel oil, it is more desirable for the old flat tappet engines. Modern gas engine oil is designed around high tech, close tolerance, roller cams and emissions requirements.

You mentioned the Wix spin on filter. Is this new and do you have the old filter assembly? If the the tractor is a bypass filtering design, the Wix filter adapter could be part of the problem. I put a spin on adapter on my Farmall C and oil pressure went way down. The original filter assembly had a small hole it for the oil by pass into the filter. The spin on adapter had a hole that was four times larger. There wasn't enough back pressure in the oil system and the pressure was too low. I went back the factory cartridge filter.

OTJ

very common for a tractor of that age. and no problem to run it.

I would stay with the hd 15w40 so that the engine will not wear more.

You 15w40 runs very very near a 30 to 40wt oil at high temperatures anyway. It also runs very near a 15wt oil when very cold till it warms up... so you will not see much improvement with a 40wt... and NO improvement with a 30wt.

If needed,, add some lucus oil stabilizer to the oil to help with worn parts to give it some addition life, and a bit more oil pressure.

Also remember that oil gauge may not be reading correctly, especially if its a china replacement.

25 lbs, working is satisfactory for that engine. 5 lbs is ok at low idle.

It's been a number of years since I've worked on the older 4 cylinder engines but I thought they where cam in block design with no cam bearings, parts search doesn't show any cam bearings.
If the engine is original and hasn't had an oil pump upgrade 40 psi is the most you'll see.
Ford shop manual list 10 psi min so it's a little low at idle, replacing the oil pump gears could fix the issue, upgrading from a gear pump to rotor pump usually increases oil pressure several lbs.

(quoted from post at 07:03:12 08/05/19)
very common for a tractor of that age. and no problem to run it.

I would stay with the hd 15w40 so that the engine will not wear more.

You 15w40 runs very very near a 30 to 40wt oil at high temperatures anyway. It also runs very near a 15wt oil when very cold till it warms up... so you will not see much improvement with a 40wt... and NO improvement with a 30wt.

If needed,, add some lucus oil stabilizer to the oil to help with worn parts to give it some addition life, and a bit more oil pressure.

Also remember that oil gauge may not be reading correctly, especially if its a china replacement.

25 lbs, working is satisfactory for that engine. 5 lbs is ok at low idle.

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Great, Thank you. I don't think the oil gauge has been replaced. Looks OEM. ALso I may run out and get some of the Lucas Oil stabilizer as you suggested while I still have the 15W-40 Rotella in the engine.

Thanks, that was what I was thinking too, so I chose the Rotella brand and the 15W-40. I appreciate the feedback. I'm sure I'll use something a bit lighter in the winter, 10W-30 or similar.

Thanks for the info., I guess I was just trying to find out if my engine had anything really unusual for an old girl of approx. 60+ yrs of age

Oh, now that's quite interesting, I may give that a try!

I got the tractor a few weeks ago and the adapter was on it already.

(quoted from post at 22:45:06 08/04/19) I purchased my '53 Jubilee from my sister and have recently been working on it. I got it running pretty well and used it for the first time with a 5' brush hog. I'm running 15W - 40 Rotella oil with a wix spin on filter kit. I noticed the oil pressure seemed very low compared to what I thought it should be. I'm running about 25 psi with hot oil at around 1500 RPM. At idle, about 5 psi. When the engine is cold, runs about 39 psi and around 15 psi. Is this somewhat typical for an older girl? runs fine, has fair amount of blow-by, not the best compression...unless I add oil to the rings. Unit only shows 495 clock hours. Any thoughts? Should I rebuild the oil pump? Just run it and enjoy it? Immediately stop using it? etc.

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It ain t no Formula One Car engine . Run straight weight 40 for a test .
Pressures sound ok actually . What does the iperaotr s Manual state as normal pressure ?

That's an interesting point. All I know is the tractor came with the spin on adapter. It has a hole, sort of an oblong opening about 1/2" long and about 1/4" wide. If I had the canister and cartridge kit, I'd give it a try. If I get a chance I will see about ordering up one.