Kubota oil psi problems

[steve01]

I've searched this on this site and have seen the problems with the plugs in the ends of the cam on the older Kubota B7100d. Mine is a 83 and has lost oil psi. It has 1300 hours on it. When you let it set and start it, if you let it idle the oil light will not come on, if you raise rpm off idle the light comes on and stays on. So here is what I have done so far.
1. Changed oil and filter
2. Cut top off old filter and looked inside, no metal
3. Removed front cover to have a look and see if plug was in front of cam, it is.
4. Removed oil pan and had a look in there no metal and is clean. Had a look at the oil pick up screen and nothing blocking it. Gave the rods and mains a shake and nothing seamed loose.
5. Put front cover back on and hooked up a old fuel oil pump to the stub that the oil filter goes on and primed it with oil and turned it on. Oil dripped from the mains and rods. Oil was running back trough the hole in the block from the front cover area. Looked inside the cover from the throttle hole and could see oil squirting from the gear in the center. Was showing about 3 psi on the gauge i have hooked where the sending unit for the oil light goes.
6. Pulled front cover again and had a look inside and looked at the gear that was shooting oil and the hole is a factory made hole. Also noted that there was a lot of oil on the front of the cam so looked closer at the cam and the plug has 2 holes in it.
So here is where i stand, I don't think the holes are supposed to be there.
Also if the front plug is bad should i change the rear also. If so what is the best way to do it remove the motor and go trough the back or pull the head and and valve train and remove the cam that way?
Here is a picture of the cam so you can see what I'm dealing with. Also I've changed the oil bypass valve, no change.

 

[SimS]

Steve;

Your symptoms seem backwards to me. Usually oil pressure is lower at idle and increases with RPMs. You say that the idiot light is off at idle and comes on at higher RPMs. I think I would suspect the oil pressure sender. I would check to see if the cam plug comes with two holes from the factory and change it if yours is bad. Then I would button the motor up and hook up a known good oil pressure gauge and see what the pressures are in psi. I'm hoping it's a bad sender. Good Luck

SimS

 

[IH3444]

You first need to remove the oil sensor sender and replace with an inexpensive mechanical gage with numerical readout to see if it is indeed a pump, gear, or whatever problem. Maybe just a bad sender.

 

[steve01]

I have a guage in where the sender goes. What is the best way to check the oil pump?

 

[automech]

what is the pressure at idle and off idle on your mechanical guage?

 

[mattman]

I think he said 3 psi on the guage.

 

[steve01]

Oil psi at idle now is 0 i do have flow but no psi. Going to go to hardware store and get some fittings and make up a bypass where the oil filter goes on and put a Gage in that junction, start the tractor, let it idle, close the valve and see how much psi i have from the pump. This will also tell me that the bypass on the tractor is working. If the pump isn't pumping enough volume I'll get a new one. If it is I guess it's time to tear this thing down and see what is what.
I have a hard time believing that with 1300 hours i need bearings.

 

[Gator6x4]

It sounds like you have covered all the bases. I would take a hard look at the oil pump. Check the pump and see if the main pump gear is slipping or spinning on the drive shaft. You may have to remove the pump from the engine to check it.

 

[Charolais]

I know nothing about Kubotas but do remember some IH oil pumps have a ball and spring in the pump. If the ball got stuck open the oil pressure would drop. Hope you find something simple. That's sure not a lot of hours on the tractor for high wear.

 

[David-Davies]

Did you check the oil pump pressure relese valve. If it is stuck open you'll have flow but no pressure.

 

[steve01]

I replaced the oil pump relief valve.

 

[steve01]

Went over everything today and checked output from oil pump and it was good. Ran a hose from the adapter i made to the oil input on the motor and had 60 psi......hooked things back up.......let it idle for 15 min and the oil psi dropped to 35psi at 1500 was at 60psi.......all that work and it was the oil filter!!
Fixed now wife says back to work ......been relaxing to long. LOL

 

[SimS]

Huh? How did the oil filter get into the troubleshooting process? I'm glad you got it fixed, but can you clue us in on the oil filter?

SimS

 

[steve01]

I used a old fuel oil pump and ran it into where the oil filter goes on and with the oil pan off I primed it up with some oil and looked up into the motor to see where the major oil leak was. I didn't see anything that was a big stream so I decided to check the oil pump so here is what i did. Pix 1 and 2 are the by pass that i made up to check the oil pump and see if it was building psi. So I set this up pulled the compression release and turned the motor over, my guage showed 60psi with the valve closed. I opened the valve and let the oil go to the motor and pulled the compression release and turned the motor over and still showed 60 psi. So i moved the oil psi guage to where the oil psi sender hooks up and turned the motor over again and still had my 60 psi. The only thing that was different was the oil filter so i changed it, now i have my oil psi back. I cut the filter apart and didn't see anything wrong with it, The only thing i can think of is it must of had mold or something in it to stop it from passing any oil. I couldn't check the by pass in the filter i wasn't very gentle when i took it apart.

 

[SimS]

Steve;

Now I get it. Great technique. Very good thinking on your part. All's well that ends well. I've heard of oil filters being defective right off the shelf but I have never seen it myself. I guess anything can happen with any mass produced product. I'm glad you're back in action.

SimS

 

[J_J]

steve01

Before changing any filters, did you have oil pressure? After installing a new oil filter you had little or no oil pressure? Only after installing the second new oil filter, you then had pressure? Did you crank the engine long enough for the first new oil filter to fill and pressurized the system? So what you are saying is that the first new oil filter was bad, is that correct?

 

[steve01]

Yes the first filter was bad. I let the tractor run for about a minute and the light never went out shut the tractor off removed the the side cover removed the oil sending unit and installed a gauge.....restarted and ran for about another min. and no pressure...removed the tubing from the side of the block that went to the oil gauge and started the tractor and nothing came out of the hole. I did have pressure before changing the oil but my light was flashing at idle, I think the tractor was running a little warm but not over heated. No whistle any way