Packard Forum Index » Pre-War (1899-1942)

I the engine does not knock when warmed up and running, it's probably OK for at least some limited driving. *

I would want to investigate the oil pressure situation before driving the car.

An odd noise coming from the crankcase area could be related to some kind of problem with the oil suction screen or related parts. Any air leak on the suction side of the pump will cause issues. Any oil pump gasket issue will cause problems. Be sure the oil pressure regulator is installed and working properly.

*The oil pump has 2 gears inside it. One of the gears is keyed or pinned to the oil pump drive shaft and is driven by it. The other gear is driven by the first gear.

If the pin or key is sheared, it may allow the gear to slip on the shaft, causing low or erratic oil pressure, or no pressure at all. It could possibly cause an odd sound, too.*

If your car has an oil filter installed, you need to check the restrictor fitting located on one of the oil filter lines. An incorrect fitting may allow too much oil to flow through the filter, which could reduce oil pressure.


Any possible problem with stuck or broken piston rings will not affect oil pressure, so long as there is adquate oil in the crankcase.

These engines are pretty much indestructible but back in the sixties, a 1940 110 engine (# C4411 - I still own it) was in my first Packard, a 1939 Six, and idling it one night beside the garage, it spun a rod bearing requiring expensive metal spraying on the journal. Just keep in mind to check everything and you're right to be mindful of oil pressure as I'm not sure my teenage self was.

Im thinking this engine must be worn. I idled it for weeks in the garage with medium pressure and didn’t think I had any major bearing issues. It purrs away under idle you would think it runs like a top. It wasn’t until I took it on a few trips around the block and all hell broke loose. Pressure is in the toilet now. Probably not enough for a decent flush 😆.

Thanks for all the info. I took apart the oil pump tonight and it looks fine. Pin is not sheared off and no visible damage or wear to the impellers. I reinstalled correct gaskets as well. When I picked the car up I dropped the oil pan and cleaned the screen and pick-up tube. Couldn’t imagine it being clogged after only a few short runs around the block. I’ve idled the car for a few months in the garage with no real oil pressure problems. I really didn’t like the way the pick up tube connected to the oil strainer. The connection was kind of loose but did not require an o-ring. Maybe I should have installed my own but I have my doubts on whether the pick up is the problem. Next I will pull the fuel pump and check the diaphragm.

Those loose-feeling pickup tubes seem odd but they worn and I've never had one fail. While the pan is off, you can also get some plastigauge to check the rod bearing and main bearing clearances. It is very easy to use and quite accurate.

If your oil is not obviously loaded with gasoline, the fuel pump is not your problem.

If the engine has been running without obvious knocks, the bearings are probably OK.

If you have oil pressure problems, and it appears that you do, it points to a problem with the oil pump or the oil pickup assembly.

Took apart the pump and it looked OK. I can’t think of any way to actually test it. Do you know of anything I can do to confirm that it is working?

Thanks again

Did you check the pickup assembly? Just 2 days ago I bought a push mower that didn't run, all it needed was the carb sprayed down with cleaner, and gas shook in the tank a few times to wash all the yard detritus out that coated the bottom of the tank and was clogging the fuel screen.