Packard Forum Index » Post-War (1946-54)

I suspect it is the stuck valve, or something similar on top of the engine due to lack of lubrication. This car sits for too long in the last 15 years at least. I only started to drive it like 2-3 months ago after wrapping up few other things in my hand.

It only makes such noise during idling in neutral. Under load either in drive or reverse there isn't such a sound. And it is warm/hot only, there isn't such a noise in cold start.

None of the mechanics brought this up and no one said they heard anything suspicious.

I bought a 16oz bottle of Marvel Mystery Oil today, poured most of them to the carburetor then fuel tank, the car ran quite smoother. But the sound of knock still exists so I bought a larger container (32oz) of Marvel Mystery Oil, poured half of those into the carburetor, and the rest to the fuel tank. After that, it still knocks a tiny bit.

Is this something to be concerned, or given ~20oz of Marvel Mystery Oil is still in the fuel tank, the sound will likely disappear soon?

(sorry about the super long link, I grabbed both audio files from Firefox page info window. Free users cannot share those audio files)

Before the MMO,
Before adding MMO

After the MMO,
After adding MMO

to be honest, the iPhone 8 barely picks up the sound.....

Try replacing a quart or two of engine with ATF and run it through a several heat up and cool down cycles without driving it and then change the oil and filter. You'll be amazed at the amount crap it flushes out of the motor. It really helped with my sticky rings after the car sat for 20+ years. Afterwards a long run with couple of quarts of Lucas Oil Stabilizer quieted everything down and helped reseat the rings.

Also you can pop off the side valve covers so you can observe if there are valves sticking, bent or misadjusted.

Thank you, that sounds like a good plan. I will do that next week (so shops are open just in case something goes very wrong)

I just opened the valve cover and everything inside looks relatively reasonable to me. Because it is at night, I can't see clearly. Everything looks like the way they should be

I rarely work on cars myself (because when I do, either it is something wrong and only I have to do it, or I will jinx the cars. I really hate working on cars after prototype testing for a few years) but Packard looks quite reasonably well engineered to work on.

You can idle it with the covers off and observe the valve action.

Look for ones that are not moving back down with their lifters.

Thanks for the tip. I am going to try this tomorrow and see

I just replaced my rad hoses & clamps and painted my transmission cooler and yours isn't bolted on correctly and the brackets have been bent to compensate, but it's still off a bit. Just an FYI in case you ever have that apart and want to correct it.

To me it looks rather dirty, you can see little specs of stuff on that closest valve stem. It could be sticky valves, or sticky/dirty lifters. It doesn't take a very bit piece of stuff to mess up a lifter.

I suspect that your ticking noise will eventually go away. An additive in your oil, such as Marvel, ATF as mentioned or AC Delco Lubricity Additive is also a good one. A couple of extra oil changes wouldn't hurt either.

A potential problem could be that there is some sludge in the oil pan. Your engine may keep picking up bit of junk for who knows how long. The best fix for this is removing and cleaning the oil pan, which is a bit of a project. You could probably check for this by sticking something in the drain hole and scraping around in the oil pan to see if there is anything next time you're doing an oil change.