Packard Forum Index » V-8 (1955-56)

Oil pressure drops at hot idle on modern cars. Note that some manufacturers rig the gauge to read constant above 7 psi.

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True. Unless, of course, the fuel mixture and throttle position screws are off, on the carb

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Very interesting, did not know that.
It sounds like Ryan's car is simply trying to stall, though, so I would not be concerned about the oil pressure, for now.

Ok thanks for the replys I think I have a good strategy. The car does have this problem even when cold so its probably not overheating. I'm going to try to adjust the idle and/or carb settings. Then I will try replacing ignition points, condensor, rotor and cap. When I first bought the car I had this problem and changed the plugs and wires and it ran fine. My guess is the car didnt like the adjustment it received from the shop.

I'll post update when completed.

Tune-ups on cars of this era happened twice a year, or every 6000 miles. Whichever came first. They consisted of:

-Inspect the spark plugs, wires, cap, and rotor. Clean, gap, or replace as required.

-Inspect the ignition points. Clean or replace as required. Reset the dwell with a dwell meter. A feeler gauge does not work for setting used points.

-Check the ignition timing. Adjust as required.

-Verify function of the distributor advance mechanisms.

-Spray the choke linkage clean with a non-residue solvent, such as spray carburetor cleaner. Do not oil. Make sure the linkage and plate move freely.

-Adjust the idle mixture screws to achieve the highest idle speed in gear, wheels blocked. Then turn the screws lean 1/2 turn at a time until the speed drops slightly. Finally, return the screws to the highest speed.

-Adjust the curb idle (in gear, wheels blocked) to 500 rpm.

-Service the carburetor air cleaner and oil breather.

-Inspect the fuel filter. Service as required.

-Apply a few drops of regular engine oil to the generator and distributor bushing oil cups.


The idle mixture and speed settings are the most relevant to your problem. Those settings change quite a bit with the changing weather and gasoline blends in fall and again in spring.

Possible Vacuum leak?

I had a rough idle problem with the wife's 55 Caribbean. I checked the plugs, points timing, plug wiring, etc. before trying what I mentioned at post #3 elsewhere on this site.

If you are near Detroit then you should check out/join the local Packard Club, they would know sources of local expertise:

Motor City Packards

But it does really sound like perhaps you need a tuneup.