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This method was recommended to me by HH56, and it worked!

Howard (HH56) is a wealth of information and has always been more than happy to help, going far beyond the call of duty as it were.

However, which method worked? Seeing all the help given, it isn't clear what you actually did to fix the problem and knowing that might help the next person so can you please elaborate?

Packard Don, good point to make clear which one I used. I was replying to Packard 1948's last post where he said he was going to try the back flow procedure. This is the one which was recommended by HH56 and worked for me.

Hi everyone!!!

We are FINALLY back at it trying to troubleshoot the low oil pressure issue on my dads 1948 straight 8.

As a review...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


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 was not the old 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 so the new pump is installed and there is not any oil squirting out of the hole.

-Removed the oil pan and the floating oil pickup tube and screen was still attached...HOWEVER...the tube connections are VERY loose.

How loose should these connections be? It almost seems that the loose connections would be a source of air infiltration into the engine oil but why did the car suddenly loose complete oil pressure...so much so that there is zero oil squirting out of the open oil pressure sender port???

So now we have the oil pan off...perhaps we should start from step one...but what would that firs step be???

THANKS EVERYONE FOR YOUR HELP AND WELL WISHES!!!

Can we assume the oil pump gears are turning when you crank the engine?

Quote:

That should be easy enough to check by looking at the distributor rotor to see if it's turning. If it is, then you've eliminated a problem with the cam or pump gears. Of course, if there had been a problem with those, it would not have run at all.

Don, the reason I asked the question was that it wasn't clear to me from the original question if the engine continued to run or was capable of running after the oil pressure went to zero.

I can say that I have not confirmed that the oil pump rotor (gears) turn when the crankshaft turns because that would involve removing the cover from the oil pump and I did not want to damage the paper thin gasket.

It seems that the replacement oil pan gasket is not the correct part so I need to order one from Max Merritt anyway so I will order an oil pump cover gasket and then watch the rotors turn as the engine cranks over with the starter motor.

What should I inspect on the inside of the crankcase since I have the oil pan off? The oil pickup pipe and the Float-O screen are removed.

The Service Instruction attached earlier in this post says "when you replace the screen make sure that the upper connection is tight, where the oil tube is fastened to the crankcase. This is particularly important in the case of the flanged connection in the Super Eight"

Is this a press fit?

Review the design. The cover is the only thing keeping the idler gear in-place. The gear will slide right off the pin as soon as you remove the cover . . . not a problem you can still run the test, but with the idler sitting on the bench. You can use a bit (not a lot) of grease to glue the idler gear into the housing during reassembly.

dp

Here is a video of the oil pickup tube.

youtu.be/Yhb6rDR8xEw

(sorry in advance but YouTube wants to show some strange "premier" of 1.30 minutes of nothing before the video starts)

Is this about the right amount of "slop" in the float-O screen and the stationary oil pickup tube? It seems a bit sloppy and if so I would think that it would suck in air before sucking in any oil...yes...no???