John Deere 1070 Low oil pressure light

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Lonnnng story short.....just had the motor rebuilt with a new/used crank, new/used block, new bearings, seals, rings etc. Upon getting the tractor back, first time i start it up the low oil pressure light is solid lit at idle 900rpms and will start to blink away when raised to around 1000rpms. The light stays unlit at higher rpms but will start blinking and then solid when rpms drop down back into the 900 range. Upon one check i let the tractor sit at 14-1500rpms for a few minutes to see if the light will come on and the engine died. I started it back up and it idled rough between 700-900 so i shut it off. Changed out the fresh oil from rebuild, which came out like a water hose, and put in some fresh delo 400. I also changed out the oil pressure sending unit and still have the same issues.

Any help is appreciated.

 

[zzvyb6]

Clogged or incorrect oil filter. Blow out the oil pressure sensor gallery with an air line to see if the sensor is not getting a true reading. Clogged oil pickup. Are you saying that the motor stalled because it seized from low oil pressure ?

 

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Clogged or incorrect oil filter. Blow out the oil pressure sensor gallery with an air line to see if the sensor is not getting a true reading. Clogged oil pickup. Are you saying that the motor stalled because it seized from low oil pressure ?

Where is the oil pickup? Sorry havnt got a repair manual and im new to tractors. Not sure why the motor stalled.

 

[zzvyb6]

John Deere Parts Catalog

Oil pickup and strainer are inside the crankcase. Your engine rebuilder ought to deal with this.

 

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Thank you!

He will be, just wanting to learn for myself.

 

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Clogged or incorrect oil filter. Blow out the oil pressure sensor gallery with an air line to see if the sensor is not getting a true reading. Clogged oil pickup. Are you saying that the motor stalled because it seized from low oil pressure ?

Ok, so the mechanic came over and put a mechanical gauge on. Upon fire up, the pressure jumped to 40 and then immediately dropped down to 30 or so and then 20. After several minutes of idling and bringing the rpms up and down, the pressure worked its way down to 13 and then finally 6 at idle which it didnt go any lower. He seems to think its ok and that once everything seats in itll be okay. Hes pretty confidant he cleaned out the passages, oil pump was good etc.

One thing he did note was the new block was slightly different than the old one. IIRC the old one had some bolts or plugs and this one had a different setup. Not sure exactly, maybe someone here knows.

Hes picking the tractor up tomorrow and gonna put some load on it and watch the gauge.

What should the pressure be at idle?

 

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So it appears were getting diesel in the oil, lots of it. Mechanic said he drained out almost 12 quarts which would explain the low oil pressure as the fuel is diluting the oil. He replaced the fuel pump as he said a diaphram was cracked and fuel was leaking into the crankcase.

Now, just got the tractor back hooked up the mower and getting low pressure again. Checked the dipstick, smells like fuel and cant get a read. Does it sound like bad injectors or injection pump? Im at a loss. **** near couldve bought a new tractor for what this is costing me.

He put a new clutch in as well when he did the engine overhaul and now the mower wont barely spin when i kick in the PTO. Does it need an adjustment?

 

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Oof. One thing after another. W/o proper tools to measure things such as fuel out-put, it is difficult to discern if your injectors are dicing out too much fuel. If that is the case, you should be blowing out black smoke. If it is not, then the problem lies before combustion and your injectors are out of the picture. You should not be losing oil pressure such as you are. There is a mechanical screw up on his part. There is a reason you are dumping raw fuel into your crank case and it seems the fault lies with the builder. He do a compression check to make sure you're getting a good ring seal?

These are the 3 main reasons I know of for getting diesel into your oil sump:
1. Fuel lift pump – The diaphragm can split providing a route for diesel to enter the engine crank case.
2. Injector pump – Injector pump shaft seals have been known to fail.
3. Damaged Injectors – Leaking injector nozzles during periods of inactivity can drip their contents into the cylinder which then runs down between the piston and bore into the sump.

As far as the pto is concerned, I do not know how JD utilizes the pto transfer. I do know on New Hollands, there is a bearing that supposed to lock the pto shaft so it can turn implements. If this bearing is shot, pto driven attachments won't turn with the force they are supposed to. Kind of easy to get to on the Fords as the pto cover plate and rocker shaft plate are all that need to be removed to get at it.

At any rate, if it was working before, this fault lies with your mechanic.

 

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Oof. One thing after another. W/o proper tools to measure things such as fuel out-put, it is difficult to discern if your injectors are dicing out too much fuel. If that is the case, you should be blowing out black smoke. If it is not, then the problem lies before combustion and your injectors are out of the picture. You should not be losing oil pressure such as you are. There is a mechanical screw up on his part. There is a reason you are dumping raw fuel into your crank case and it seems the fault lies with the builder. He do a compression check to make sure you're getting a good ring seal?

These are the 3 main reasons I know of for getting diesel into your oil sump:
1. Fuel lift pump The diaphragm can split providing a route for diesel to enter the engine crank case.
2. Injector pump Injector pump shaft seals have been known to fail.
3. Damaged Injectors Leaking injector nozzles during periods of inactivity can drip their contents into the cylinder which then runs down between the piston and bore into the sump.

As far as the pto is concerned, I do not know how JD utilizes the pto transfer. I do know on New Hollands, there is a bearing that supposed to lock the pto shaft so it can turn implements. If this bearing is shot, pto driven attachments won't turn with the force they are supposed to. Kind of easy to get to on the Fords as the pto cover plate and rocker shaft plate are all that need to be removed to get at it.

At any rate, if it was working before, this fault lies with your mechanic.

Thanks for your help. So you dont think that the fuel diluting the viscosity of the oil could be a cause of low oil pressure after warm up? He says after he changed out the fuel pump he got 30psi oil pressure after warm up. Now i know thats not the case since fuel is back to entering the oil. On start up ill get a good puff of black smoke but after that the tractor seems to run good and only light bits of smoke on ramp up of rpms.

 

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Thanks for your help. So you dont think that the fuel diluting the viscosity of the oil could be a cause of low oil pressure after warm up? .

You are welcome. Sure it can. Thinned oil can reduce pressure. If you are getting a good amount black smoke at start, fuel is puddling at the injectors. Just about all tractors can throw black smoke at start up but it clears in a second. Black smoke is a condition of too much fuel. Here's what you can do: drain the oil making sure you have sufficient fuel in your tank. Once the oil is drained, put back your drain plug and let it sit for a couple 3 days. Go back and unplug it. If raw fuel comes out, then you know your problem is not combustion related and may merely be exacerbated by running. I would side with leaky injectors if this happens.