ROG100

Hi Y'all,
I have a friend and customer in FL with a problem of no oil pressure on an 81.
He removed the oil pan, screen and the bottom portion of the oil pickup to replace the oil pan gasket. Engine ran fine before and had normal levels of oil pressure.
After reassembly and cranking without the fuel pump he is getting no oil pressure on his guage and the low oil pressure red light on the dash comes on.
He also ran the car for a few seconds and still the same result.
Assuming the sender is working (was before and was not touched) and the red light comes on.
Talked with my local experts and we concluded that its sucking air at the top of the oil pick up as the seal may have be dislodged/disintergrated. To prove the theory car was filled with an additional 8 quarts of oil to a level above the seal - we think.
Total 16.5 quarts. Still no oil pressure on cranking.

How important is the oil pick up pipe at the bottom? Reassembly seemed OK but could have got screwed up. How much oil to cover the top seal and hopefully get oil pressure. Once we prove the theory the engine will be taken apart and new seals are on there way.

Thoughts please and thanks for the help.

killav

Hey Roger,

Did he remove the oil pick-up for some reason? I don't remember having to do that during my GTS baffle/real gasket install. Maybe the "float" material disentegrated letting the sensor bottom out all the time. Nothing to make the sensor "float". If there was truly no oil pressure, the engine would start to rattle almost immediately I think. The valve train mainly. I would double check the wires to the oil sensor on the pan and make sure they were not pinched somewhere.

Edit: After re-reading, maybe I did have to remove the bottom portion of the oil pick up, I just can't remember. I don't think this would cause a complete loss of oil pressure even if it was leaking.

Lizard928

I would be inspecting the wires on the pressure sensor first, they are easy to break after all these years.

Mike Simard

I don't have any answers but that pickup tube doesn't fit very deep into the engine at the top of the pickup tube and if the single bolt right there weren't installed it could not drop into place even if the other 2 were installed. Did your friend take the whole pickup tube off?

marton

Last time I changed a pan gasket on an 83 I did not need to tuch the oil pickup?

As somebody said if you run the engine with truly no oil pressure then the hydraulic lifters will sound terrible.
Is there a pipe somewhere you could take off to check if there is oil pressure; oil cooler pipe is no good because there is a temp controlled valve.

if you lose the oil sensor connector I think it shows max pressure not no pressure.

Marton

Gretch

Pull a valve cover. Crank the engine over with no fuel pump, see if you get oil in the head gally.

soontobered84

My vote is for bad/faulty sensor/bad wires to the sensor, etc. No oil to the top of the engine would be easy to hear.

ROG100

Sensor wires appear to be fine and we are getting the red light which means one of the connectors at least is OK. IIRC one for the light and one for the guage.
Plenty of lifter noise when cranked.
On the older engines the pick up has to be dismantled to remove the oil pan as it protrudes through a wire mesh grill and into a plastic flower petal shaped collector at the bottom of the oil pan.
He only removed the bottom part of the oil pick up and did not touch the top where it attaches to the block. In putting it back together he may have moved or dislodged the seal at the top of the pickup.
The sender reading is saying NO OIL PRESSURE = red light and the guage is at zero.

Me thinks that a trip back in is in his future 8>(

heinrich

So lifter noise despite plenty of oil? The oil isn't getting to the oil pump. Btw Merry Christmas Roger and family

WICruiser

Lifter noise confirms the gauge and light indication of no oil pressure. I think the cause is only a matter of curiousity as the pan needs to come off to sort out what the problem is and get it resolved. Worst case scenario is that he removes the pan and all is good, then the pump would be suspect, but I would not start anywhere except where the recent work was done.

heinrich

Rog at this point he may want to inspect the bearings.

killav

He didn't leave anything (like a rag) in the pan did he? You remember my Blue paper towel ordeal.......

Jim M.

When you do new work and then develop a new problem, always go back to the work you just did! My guess is the oil pick-up seal was damaged or dropped during re-assembly. I would also drain the extra 8 quarts of oil out of the pan (need to drain it all to get at the pick-up). Adding that much oil will force the crank to hit the oil resulting in almost immediate foaming of the oil.

Jim Mayzurk
93 GTS 5-spd

Schocki

Hi TX gang!

If there is a lot of noise from the engine while cranking or running, then there is no oil pressure in the system. I would also vote for a faulty seal, because the snorkel was removed.

Other option is the oil pressure valve, if that baby is stuck open there is no oil pressure build up from the pump.

ROG100

Hi Schocki,
How can we test for the oil pressure valve my good friend?
Roger