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

Brought the 53 from dave moe home pulled plugs gone through 2 gals of mystery oil down plug holes, drains into block but motor is still stuck.Anyone have any ideas?Thinking of pulling head to see what pistons look like.

My suggestion is to drop the pan, take the rod caps off and try to spin the crank to see which piston is stuck. When you find the stuck piston, remove the bearing and tap the piston up from the bottom. Use a piece of aluminum or wood against the rod to protect from damage. You should take the head off also. After the piston is out, you can hone the cylinders and re-assemble the parts. Don't hammer down on the pistons because you might put a hole in the top of the piston. John

I agree with John's advice. If the engine sat for long, especially in a humid condition, the chances are excellent that the rings have rusted to the cylinder walls. Lots of snake oil (PB Blaster would be my choice), patience, and gentle persuasion should do the trick. If permanent antifreeze got into the combustion chamber (for example, from a blow head gasket or crack) then the chances are excellent that a piston has corroded, swollen, and will most likely have to be destroyed to remove it - I hope that's not the case, it can be a bear to remove especially if it's midway or lower in the bore.

My engine was stuck when I got it. A little ATF in all the cylinders and let it sit for a few days.

The I used a breaker bar on the crank bolt gently rocked it back and forth a little bit each day until she broke loose. Motor runs fine, and I never pulled the head or opened the motor except for cleaning out the oil pan and adjusting the valves.

Obviously your results may vary as you never know how long or how bad the motor was stuck. If it had been left opened (spark plugs removed) and some water got in there, or there was a headgasket leak that let coolant into the cylinders which created a rust issue, then it may not be as easy as it was for me.

No need to remove head. REmove valve cover. Free up valves or make sure valves are not stuck. Check LIFTERS too. Remove all sparrk plugs. Put at least 75 PSI on each cylinder over nite for several days. BE PATIENT. It will loosen enuf to move gradualy then faster with wrench.

I've at least 6 different engines this way over the years.

IT is the VALVE TRANE to be careful of because it damages easy if forced.

Pulled the head off to see if pistons are bad have one cylinder still holding mystery oil all others are dry. going to use liberal amounts of pb blaster on it see what happens. I was going to regasket the engine any way.

FYI: For the ATF guys. We did some tests and thinning ATF with 10-15% naptha or mineral spirits has better flow out/wetting than straight ATF. The published 50-50 ATF acetone mix as a sub for mystery oil is not one phase and will quickly separate on standing, plus it's vary flammable.
You can't really tell internal condition, if it just turns. That's playing the odds. It just a discriminator for big trouble or you're taking a chance with this one. Safest, but costliest, is to pull apart. A bore scope is a handy tool not found in most hobby tool boxes.

Jim, good suggestions, but I don't think a bore scope will work on this engine. The spark plugs are located over the exhaust valves in the Packard straight-8s, and doubt the scope will be able to see into the cylinder. Removing the cylinder head is the best way to see the condition of the engine internals. Fortunately, this is not a complicated job.

(o{}o)