Re: 55PackardGuy's '54 Clipper Deluxe

Posted by 55PackardGuy On 2014/8/14 20:49:42

A couple of developments:

I had the new oil pressure sending unit put in. If anything, the warning light stays on more than it did before. I hear no difference in running or starting, but the light says what it says. The new sending unit is supposed to kick in at 20 psi. I don't know if that's the same as the original.

I have narrowed down a few options:

1. Get a mechanical gauge. Maybe NAPA or Autozone might have one? This would tell the tale, but at a cost, and it doesn't pinpoint where the pressure drop might be. It has occurred to me that all this has happened with the combination of 3 things:

a. Doing an overnight "soak" with Marvel Mystery oil in the cylinders, then running it until it stopped smoking and up to full operating temp on the road.

b. Changing the oil
Note 1: I went from 30 weight Havoline to 30 weight Valvoline. Both times with a bottle of STP added. I had no problem before or after adding STP with the Havoline, but it was in the fall/winter months.
Note 2: At this last change to Valvoline, I also added about 8 oz. of MM oil. Then, after the oil light came on, one bottle of STP. The oil is currently right up to the line and quite clean. (Only about 100 miles on it.)
Note 3: The oil light started "flickering" at idle after the oil change. I was notified elsewhereon this site that the flickering was considered normal by Packard in very hot weather at idle. Eventually, over the course of longer drives, the light came on after driving a few miles and stayed on at higher RPMs.

c. Hotter weather than I've ever run it in before.


2. Find out if it just doesn't like Valvoline straight 30 weight by doing an oil change to something better/heavier.


3. Dropping the pan and checking the condition of the oil pickup screen, oil pan, and (shudder) bearings. Compression check was done after the flush and oil change, stone cold I got readings from a low of 115 to a high of 125. Variation could be due mostly to a crappy old compression gauge.


4. Ask you fellows what may be a cause of oil pressure drop across the sending unit. Could some piece of crud blocked something in a line?

Maybe if someone could point me to a place that would have a mechanical gauge on the shelf for a reasonable cost, it would start things moving tomorrow.