Packard Forum Index » V-8 (1955-56)

"For a more thorough diagnosis, check the hot, idling oil pressure with a good reliable mechanical gauge rather than relying on the electrical resistance gauge. And then check it again at the front of the driver-side cylinder head where the line goes to feed the oil filter. A hot, idling main pressure of 35 psi or more would be very comforting, and about 7 psi or more at the cylinder head feed to the filter."

How and where do you check the "hot, idling oil pressure"?

So much to learn!

HOW - buy or borrow a good quality mechanical oil pressure gauge, fit it with a flexible line, and install it temporarily in place of the sending unit for the electric dash gauge. WHERE - the electrical sending unit is at the rear top of the engine, behind the intake manifold and adjacent to the crankcase breather tube (kind of opposite the distributor). It has a single wire attached to it at the top of it.

For the pressure at the lifter galley, remove the inlet line to the oil filter and install the gauge. This is on the front face of the driver's side cylinder head behind the water pump manifold. Just follow the two lines from the filter - the one that installs on the vertical front face of the cylinder head is the one you want - the one that installs horizontally near the oil filler tube is the return line, that's not the one you want.

I'd bet someone will post pictures for you, I don't have any handy.

Progress Report: tentative Triumph.....

I overfilled by slightly less than a quart and drove to the gas station, did a couple of errands and came home. About 15 miles, with three stops.

Previous oil pressure showed on the gauge at idle with the needle at about 11:30; now it shows at about 12:30.

thus far,,,,,no tappet noise.

I'll let you know how we do in the parade on the fourth.....

Kind of sounds like the oil pump sucking air.

Glad to hear the news, many of us routinely run a bit over full on the V8s. My own 56 with about 90,000 miles has no lifter noise but even so I always overfill a bit.

Just got back from the local 4th of July Parade with another 56, a crawl at 90+ degrees in and out of the sun.

No tappet noise, but both cars got very hot. My temp gauge got to about 12:30 and my foot never touched the gas, just the brakes. Car pinged for two blocks then cooled a bit and ran fine.

I can only imagine the anguish of a straight eight owner.....

I can only imagine the anguish of a straight eight owner.....

Not sure what you mean by that, care to elaborate? The straight 8s were in production far longer and thus had time to be completely sorted out, problems with them are few and far between. Glad your car did fine in the parade, I did one as well in my 34 Eight, about 3.5 miles of creeping and stopping, 95 degrees more or less, no problems either. Parades on hot days are good tests for our cars, and for outselves.

My 1950 356 straight eight runs quiet and cool even in 95 degree heat! Of course this is since I replaced the thermostat that wouldn't open, the radiator cap that didn't seal, and the hydraulic lifter that wouldn't lift. Prior to that, I was driving a steam belching machine that sounded like a Gatling gun.

Maybe the driving sorted it out? Some lifter annoyance is common on a hydraulic lifter engine that has been out of commission for months or years.

I just had the same problem ironically, with a 318 equipped Dodge pickup, that had been off the road for almost a year. At first the lifters would stick when starting from cold but quiet down after a couple of miles of slow driving. They got better the more I drove it and after a few months, are quiet as a new car.

In the case of sticky lifters a can of Bardahl or Rislone in the crankcase, a shot of Marvel Mystery Oil in the gas and a long drive can work wonders.

I can only imagine the anguish of a straight eight owner.....

Not sure what you mean by that, care to elaborate?

I have always been told that the straight eights were notorious over heaters. Is that a myth involving maintenance issues?