No oil pressure after rebuild

[santagrant]

We are not getting any oil pressure after a total rebuild. The engine was rebuilt many years ago but has been properly stored in a plastic bag in a climate controlled storage. Took out the pressure sender at the right rear of the engine, and nothing is coming out.
Any thoughts?

Grant

[Dan J]

Silly question But is the oil inlet ( below the cooler) Plugged?

[Walt Fricke]

Can we assume that this engine is installed in a car, and that before starting it (but after filling the tank with oil) you pulled the spark plugs and spun the engine with the starter just to get some initial oil everywhere? And didn't see any pressure on the gauge after doing that, plus no oil leaking out (which is the more usual test) from what amounted to a loosened fitting?

That's a problem, for sure.
What if you crack the scavenge pump outlet nut? If you don't get oil there, either the pump is really trashed or the connection to the IS shaft is broken or, as Dan wonders, the oil inlet is plugged.

What happens when you pull the engine sump drain plug or plate? Oil come out?

There are two pressure reliefs - the vertical one which sets the working pressure, and the horizontal one which relieves any overpressure the other one doesn't handle. Both are accessible externally. When you crack those, what happens? One of them (the vertical one? - can't remember) is usually sort of dry below the pressure piston. The other one usually has a bunch of oil below it.

For that matter, you could pull the idiot light sender at the front of the engine - that is very close to the outlet of the pressure side of the oil pump, and turning the engine over should cause oil to come out of it (even turning it over by hand for a while)if oil is getting to and through the pump.

[Trackrash]

What Walt said.

But if if were me, first I would pull all the plugs, remove the oil pressure warning switch at the front of the motor. Then crank it with the starter for a while.

If no oil comes out, remove the thermostat and repeat.

If that fails use an endo scope to try to see if the oil pump gears are turning.

Let us know what you find.

[DRACO A5OG]

Wow, what a nightmare

[boyt911sc]

Originally Posted by santagrant

We are not getting any oil pressure after a total rebuild. The engine was rebuilt many years ago but has been properly stored in a plastic bag in a climate controlled storage. Took out the pressure sender at the right rear of the engine, and nothing is coming out.
Any thoughts?

Grant

Grant,

You did not specify what engine is involved so I will be assuming it has an oil sump plate cover. If I were in your shoes, I will do the following:

1). Check that you have sufficient oil in the oil tank.
2). Remove the oil pressure switch (which you did) and the oil return from engine to oil tank.
3). Crank the starter several times and observe oil flow from the oil line outlet. If there is oil coming out, the oil pump is turning. If no flow, it could be restricted or the pump is not turning (?).
4). Drain the oil and remove the oil sump drain cover (if any). Look at the drive shaft to the oil pump when cranking the starter.

I could give you some specific procedures to test the oil pump in situ but that could wait. Keep us posted. Thanks.

Tony

[Tippy]

After confirming everything mentioned above, have read that Victor-Reinz had an issue with the oil pump big, squared o-rings not sealing in case halves causing pump cavitation/lack of suction.

[santagrant]

Thank you all for your calming reassurance that it was a simple problem - AND IT WAS!!

When the "S" line was installed, a plug in exit port of the oil tank was left in blocking oil from going to the engine. Should have figured that out when seven quarts of oil showed over the top mark on the dipstick!

We got sidetracked last night watching the Oscars. This morning after reading all the posts Dan J, the first responder nailed it. But thank you all for your kind thoughts and worthy responses - all were gratefully received. This engine was the 135th I had build and such a rookie mistake is causing me to question my abilities at 74-years-old!

Thank you all again!

Grant

[DRACO A5OG]

"74", eh, you are forgiven. Wow I have hope now. Outstanding keep it up Youngster!

[Walt Fricke]

Nothing like a lifetime working on customers' cars to give Dan insight into what kind of simple mistakes can happen.

[Walt Fricke]

Gordon's mention of using an endoscope is worth extra mention. When these used fiberoptics and were new they were expensive. Medical grade stuff still is, of course. But nowadays they use a video camera, which basically is cheap, and more or less any old cable will connect to the USB port of a computer, a laptop, a tablet, or a smart phone to provide a screen and a way of saving pictures - or even videos. The least expensive one I say was $5.00! Most are less than $30. A 5.5mm head has a 0.3 megapixel camera, while those in the 7mm to 9mm diameter usually have a 3MP camera. Focal length seems to be set by the lens over the camera part, though in about every case depth of field is small, so you can't get too close or too far away to see much. All have bright, and controllable, LEDs - six of them - around the camera, so lighting isn't much of an issue. Really handy for diagnosis of mechanical issues sometimes.