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Greetings,

It has been a long time since I posted and that is because my dad's Packard has been running nicely these last years...until now...

It seems that the engine has suddenly lost all oil pressure...like zero oil pressure.

The background is that a couple of years ago we had the engine rebuilt and it was running perfectly. One day my dad started up the car and about 1/2 block away the oil pressure dropped to zero.

The car is a Packard Engine Serial Number book calls the engine a "1948 22 Series" 327 CID, 145 HP, Super Eight L head, 5 bearing, solid lifters Casting number: 389803 11-17-48. It has a remote oil filter unit that is plumbed like the attached picture (this could be the issue however we have not looked into it).


To troubleshoot, we have removed all sparkplugs and when using the starter motor to spin the engine and performed the following steps:

-Verified oil level is at the max on the dip stick.

-Checked the electric oil pressure gauge and when the sender wire is grounded out the gauge will peg at max oil pressure...so it is not the oil pressure gauge.

-Replaced the oil pressure sender unit and still no oil pressure...so it is not the sender unit.

-Removed the oil sender unit and cranked the engine over and no oil is squirting out of the open hole...so the pump is not moving oil.

-A local Packard guy suggested that perhaps the oil pump pin has sheared off so my dad ordered a new pump and when the new pump arrived I removed the oil pump and stuck a wood dowel inside the impeller hole and tried to turn the drive gear and verified that the pin had not sheared...so it is not the oil pump.

-Since he had a new pump already bought he wanted to use it so I squirted oil into the impeller holes and the shaft and reinstalled the replacement oil pump (wow that is a HORRIBLE JOB ...trying to get the pump gear meshed with the distributer slot and then getting the teeth to align to get the distributer rotor back to the same position...) so the new pump is installed and there is not any oil squirting out of the hole.

Today I will read about the remote oil filter assembly and also read about the oil pickup tube as perhaps that could have fallen off.)

Knowing that you all are the depository of all Packard knowledge out there I wanted to reach out to the experts and get your advice...any help would be greatly appreciated.

THANKS EVERYONE!!!

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If the filter assy had a problem the only part that would be oil starved is the lifters because the oil pressure directly from the pump is in the bottom port where the sender is located. All of the engine parts other than the lifter gallery gets oil directly via runs cast in the block and fed from either that transverse run or the long length running on the passenger side directly above the oil pump. The lifter gallery is fed either thru the filter and into the upper port on solid state lifter engines or via a short pigtail connecting the two ports on hydraulic lifter engines and those with no filter.

I would say the oil pickup is a good place to start. If you have replaced the pump then that plus the drive gear and pressure relief valve should all be out of the picture. With the passages all cast in the block, no tubing is involved except the floating pickup and it's connecting assy. As I recall there is a pin or cotter key that keeps the floating screen assy on the tube assy feeding into the pump intake. Perhaps that pin or cotter key loosened and screen assy fell off.

HH56, Yes you were one of the experts I remember who was exceptionally helpful back in 2016 when I did all of the work on my dads car.

>As I recall there is a pin or cotter key that keeps the floating screen assy on the tube assy feeding into the pump intake. Perhaps that pin or cotter key loosened and screen assy fell off.

Does anyone have any pictures of this contraption?

The service manual is silent on the pickup assembly and has no pictures and I cannot find any reliable pictures on the Google.

So to understand this oil system it helps me to spell it all out so please correct me if I am wrong...

There is a "floating" oil pickup screen assembly (why does it float) and from there the oil is sucked up through the screen and flows to the oil pump.

The oil pump is externally mounted on the right side of the engine near the front and it has a drive gear that is driven off of a matching gear on the camshaft.

The oil pump drive gear serves two purposes...
-first it drives the oil pump impellers and
-second it has a male slot in the center of the gear that meshes with the female slot in the distributer drive shaft (this was the "union" that caused so many bad words to get uttered during the reassembly...fortunately I took a picture of the distributer rotor position before I removed the oil pump).

-Once the oil is sucked through the impellers in the externally mounted oil pump the oil is now essentially unfiltered and pressurized and it now flows past a spring loaded ball bearing type pressure relief valve.

-The pressure relief valve is non-adjustable and is preset from the factory with a certain tension on the spring. If the oil pressure is too high the pressure will force the ball bearing off of its seat and that excessively pressurized oil will be dumped back into the oil pan.

-Oil flow that meets the oil pressure requirements of the overpressure relief valve will be routed back into the engine where it will take one of two paths...

-The first oil path is the oil gallery that runs along the right side of the engine parallel to the oil pan mounting flange and this is the path that feeds all of the internal components of the engine other than the lifter gallery.

-The second oil path is straight through the block and out of the other side (left/driver side) of the block at the lower oil fitting port and here will be an externally mounted Tee fitting.

-The first leg of the Tee fitting will have installed the oil pressure sender unit.

-The second leg of the Tee fitting will be one of two designs depending on IF the engine has an externally mounted oil filter assembly.

-On engines NOT equipped with an externally mounted oil filter assembly there will be a small "U" shaped pipe that will direct the oil right back into the engine through the upper most oil fitting port on the engine and this feeds the lifter gallery.

-On engines that ARE equipped with an externally mounted oil filter assembly will have an external pipe that routes the oil to the top of the externally mounted oil filter assembly and the oil will circulate around the outside diameter of the paper filter element and then flow through the paper element toward the center and once in the center the oil will flow down through the second externally mounted oil pipe through the upper most oil fitting port on the engine and this feeds the lifter gallery.


Did I get this right???

So not all of the oil flow is filtered???

So just oil screen is the only thing that filters the engine oil going to the crank and camshaft bearings (YIKES)!!!

If this all is accurate then replacing the oil pump will have removed the oil pump, the oil pump gear drive, and the oil pressure relief valve from the equation.

Perhaps the Tee fitting to the oil sender is blocked by grit???

If I remove the lid from the oil filter and crank the engine with the starter motor and if the oil level in the filter increases then I can confirm the oil pump is working???

If the oil level in the filter does not increase then it is time to take off the oil pan...drats!!!

SORRY for the long stream of consciousness but is does help to understand the system.

Packard used the bypass system where about 10% of the oil is passed thru the filter and the rest is delivered straight to the bearings. Eventually all the oil makes it thru the filter so it evens out over time. Back in the day filters were not so common and Packard was not the only mfg that had them as options. Packard made them standard on engines with hydraulic lifters and optional on models with solid lifters. The filters were plumbed in many different ways in the early days. The 40 356 engines with hydraulic lifters is where they started having issues with filters clogging and low flow resulting in noisy lifters. Several filter changes and replumbing attempts were made before settling on the flow path and characteristics that lasted on all engines thru 54.

Check out this thread. It is a later engine but same block and setup as your 48.

There are a couple of photos in the thread that show the pickup clearly but the only one I have showing the pickup mounted in the entire assembly as it sits in the car has the pin or cotter key area kind of hidden. My photo was taken by a friend for an entirely different reason. It shows what can happen in long sitting engines when mice find an opening and take up residence.

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There is an approx 12" long tube that connects the pickup assy to the oil pump port in the block. It has a compression fitting at each end which could conceivably come loose. Even if the floating pickup has fallen off, the end of the pickup assy will still be be submerged.

You could in a few minutes remove the the oil sender union out of the block and crank a bit to see what happens.

The floating pickup was to gather clean oil off the top and let chunks -if any-settle.

Partial flow filters work on the same principle as swimming pool filters: they were to filter out the slow accumulation of dust, wear particles and sludge to keep the oil clear. Engines are not supposed to be throwing chunks off into the oil any more than kids are supposed to throw dirtballs into the swimming pool.

>You could in a few minutes remove the the oil sender union out of the block and crank a bit to see what happens.

Yes I remove the oil sender and had the open tee fitting block looking straight down the opening and crank the engine over and not even a dribble

With the oil level at completely full are you saying that the 12in oil pickup pipe would be covered in oil? I was considering overfilling the crankcase by 2 quarts to see if that would allow the oil pickup to suck oil

The upper end of that pipe is about level with the oil pump so you would have to greatly overfill to reach it.

Before going to all the work of removing the pan to check the float pick up screen and pipe, I have a recommendation.

I think that when you installed the new oil pump the pump may have lost its prime even though you squirted oil onto the gears. I recommend re-priming the pump. This can be done two ways.

One is to remove the pump cover and fill the gear chamber with a light grease.

The other is to pump some oil back into the pump.

Remove the fitting and tubing that supplies the filter and gauge sender unit.

Screw in a ⅛" NPT barb fitting. Slip a 5/16" or ⅜" hose on the fitting.

Then with an oil dispenser (pistol type oil can or other) pump about a quart of oil into the hose.

Reconnect the fittings, tubing and gauge.

Regardless of the method used crank the engine over with the spark plugs out. Watch the oil pressure gauge for a reading or remove one of the oil gallery plugs on the lower RH side of the engine and watch for oil to be pumped out.

If this does not work, check the pressure relief valve in the pump. It could be stuck open.

If none of this works then drop the pan and see what is going on with the oil pick up float screen and pipe.

One more thing: The pump cover gasket is very thin - like printer paper thin. The pump may not be able to prime if a too thick of gasket was used.

Hope this helps.

Just for your information on the Float-O Screen, from Service Letter Vol. 18 No. 7, July 1944.
Wes

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As always... very grateful for the advice.

I will try the back flow to prime the oil pump first then if that doesn't work I will do the oil pan removal.

THANKS AGAIN