Packard Forum Index » V-8 (1955-56)

what are reading for oil pressure? does it drop off when the noise stops?

the fact that it happened right after the oil change still makes me think a plugged lifter or two. i, admittedly without paying attention, changed my oil and added a very high detergent oil which picked up sludge and carried it into the lifters tiny ports. i also had the noise come and go, after a few minutes of running, and the noise would move just as you describe.

really the only way you will be able to tell is to pull the pan. it gave me tremendous piece of mind to see that all was ok in terms of the bearings. Im also really, really, really glad because i found several of my vacuum pump/ oil pump screws were coming loose. there were no lockwashers or anything, and i guess they had vibrated loose.

you could pull the valve covers and look carefully to see if any valves are moving strangely.

The fact that the noise stopped if only momentarily with the addition of MMO, which would thin the oil, does not seem to indicate a worn rod bearing. As Owen mentioned a good mechanic should be able to tell the difference. An old and simple method of diagnosing a rod knock is to simply short the spark plug and the noise should be reduced or eliminated on that cylinder. A main bearing makes a dull thud type noise not at all like a lifter. A rod bearing makes a metallic knock. I am inclined to think that since the sound went away when the MMO was added a lifter is the culprit. Pulling the pan and checking the bearings and presence of sludge etc. as advised by others more knowledgeable than me is probably a good idea.

clipper47, you are right on the money. i forgot about the sparkplug test. on my car, the problem was definately the lifters, and the spark test made no difference in the noise.

When I bought my 47 I had a very severe and unPackard like embarrassing lifter clatter. I was advised to put a quart of ATF in the oil and drive the car a few hundred miles. One day while on a highway trip the noise suddenly stopped. Soemtimes with an engine that has not been driven in years, as mine was, the lifters simply clear themselves. I did also drop the oil pan and clean the sludge of 50 years out before driving the car and I think this is the place to start especially on those old inline eights with the long flat oil pan.

absolutely, and i kind of wish i had dropped it sooner.

my friend has a 54 288, and i know what you mean about the oil pans being huge.

the v8s do have a deep sump and a very flat plane above it. i have to say there was very little sludge in mine, but it was enough to cause problems.

What happens if you overfill it 1 quart of oil?

Thanks for all of your suggestions. Shorting the plug is a good idea and will try it as well as pulling the valve cover. Dropping the pan unforunately has been met with the "how the hell" look from the mechanic and is beyond me as it has been discribed earlier (not an easy job and I am less than a novice mechanic) if the confirmed problem of the leaking rear engine seal requires an engine pull could the pan be them checked and not mess with the stabilizers or starter motor (two things that are at this point not wrong with the car). If you tell me to paint myself blue and run in a circle I would at least think about it if it could help. Does the engine need to be pulled to fix a leading rear engine seal? To answer the question about the oil pressure, it increased slightly after the MMO was added and the engine seemed to run smoother. Since then there is a definite side to side movement as perhaps one cylinder is not firing???

i dont know ont hese engines specifically because im afraid to try.

on most engines, you run the serious risk of having the crankshaft hit the oil in the pan and churn it into a froth. this froth gets sucked up by the oil pump, and because of the aeration, it has almost no lubricating properties. it CAN wreck your engine if severe.

some engines have enough clerance so the crank wont hit the oil, but im not sure on these.

I put in five quarts of regular oil before the noise, then removed a quart and added MMO. I have since added 1/2 quart extra of MMO and it again stopped the clicking for a few moments. Should a bad bearing start and stop and what about the increased engine vibration? Even with the click before I started you could put a glass of water on the air cleaner. I have also had the mechanic try an engine flush and put in some super lubricant that he suggested and it seems to be getting worse.

i do not think a rod knock should change or start and stop.

drop the pan, then use my diesel/mmo flush and maybe drop that mechanic too. starting to sound kind of shady to me.