Packard Forum Index » V-8 (1955-56)

I don't know what Packard you have but I'm guessing because you said "H" and "D" that you have a 56 with pushbutton? Yes, using "H" will give much longer transmission life if you've got the least tendency towards jack-rabbit starts.

I understand exactly what Turbopackman is talking about with the clutch disc and in fact I had the same situation myself years back and cured it the same way, but its pretty easy found to differentiate between clutch sounds and preignition, the former is more of a groan and you described rattles - so I'm sure you're experiencing preignition.

Perhaps you should see an old-timer mechanic if you're not up to this, but timing is retarded by loosing the distributor hold down clamp and rotating the body of the distributor. From your description you need to retard the spark, that is, to have it occur later. So rotate the distributor body A DEGREE OR TWO in the direction that the rotor rotates. But better mark where it is first in case you overdo it. I just loosen the clamp slightly and tap the vacuum advance lightly with a small hammer. But you can be a lot more precise by using a timing light.

No, I don't have pushbutton. The shift arm, with P-N-H-D-L-R gears to choose. So, leave it in H, yes? Although, in answer to your question about having a lead foot. Maybe a long time ago, but I've mellowed since then. I don't drive fast, except on the freeway.

What you describe as to timing sounds easy enough. If I just had a pic. Will check Youtube real fast.

Good point! I've mellowed a bit as well.

Look, if you're apprehensive about checking and setting the timing, why not just first confirm the diagnosis by taking a tankful of higher octane gas? If the noise goes away or is minimized, it's timing. If not, it's something else.

With preignition, it occurs more severly when the engine is under load, and decreases or stops when you ease off on the load, for example, back off on the accelerator.

You might also consider using a vacuum tester to make sure the distributor vacuum advance diaphram is not leaking.

I have a problem with my 56 Patrician.Upon hard acceleration, I get a severe vibration that smooths out after a few seconds. If you kick it down at high speed, it jumps and there is no vibration.Any thouhts?

Sounds like the same issue I am having. I feel convinced it is pre-ignition at this point. I will mess with it tomorrow.

Owen, also, I have no fear adjusting timing. I just haven't done it before, but it seems all it is is loosen a nut or bolt and turn the distributor in direction of rotor 1 or 2 degrees. No big deal.

A friend mentioned vacuum advance as well. He says disconnect hose, suck air, watch spring move, put tongue in way to plus hose, and see if spring moves. If so, could be leaky diaphragm. I am paraphrasing out of memory, but sounds easy, too, so I will check as well.

Thanks.

I'd think about high tension cross-fire.

A friend mentioned vacuum advance as well. He says disconnect hose, suck air, watch spring move, put tongue in way to plus hose, and see if spring moves. If so, could be leaky diaphragm. I am paraphrasing out of memory, but sounds easy, too, so I will check as well.

Actually, you don't have to remove the distributor cap and watch for the breaker plate to rotate to check, though that's a good method and checks the distributor internals as well. Simplier test is to determine if the unit will hold a vacuum; put a rubber hose over the steel line to the diaphram, draw a vacuum with your mouth and immediately put your tongue over the end of the hose. Wait a few seconds and release your tongue; if you hear the hiss of air going back into the unit, it held vacuum and is OK.

I can do that, too. Thanks.

Check #5 and #7 plug wires. They go to the 2wo rear most cylinders on the left side of the V8. These 2wo wire must NOT touch each other at any point. Keep them seperated by at least 1/4 inch or more.

#5 and #7 plug wires touching are often over looked and cause problems because they are so close together. Usualy causes a pulsation or rouff engine performance. Especialy at idle and very poor fuel economy.

All tho much less likely check #8 and #4 plug wires too. Check ALL consecutively firing plug wires to be sure they are not touching each other at any point. 5 and 7 are the usual culprits. Hmmm. maybe i should go cheque my own. I know 5 and 7 are ok but i've never checked the others. Geeeez.

So many options. We'll see where it goes. One thing I did not mention is my friend, who is a bit more savvy than me, mentioned a week ago that he thought the exhaust smelled a little rich. That makes me lean toward timing based on what all of you have said concerning pre-ignition.