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Our '37 Super Eight has an intermittent problem of the #7 exhaust valve sticking open if the engine is not run for several days.
At other times, the engine starts fine, but a mile down the road the valve sticks open.
Sometimes, letting the engine cycle down to idle...the valve releases and runs smoothly.

I assume some varnish has built up on the valve.
When it is stuck open, I am able to remove the plug, use a small wood dowel and a light tap always closes the valve...for an indeterminate time.

Yes, I could remove the head, remove and clean the valve, but am hoping that someone has discovered a chemical solution for dissolving the residue.

Have you tried Marvel Mystery Oil in the crankcase and in the gas? A lot of guys swear by it.

There are other products that free sticky valves like Bardahl, Rislone etc.

Maybe you need to drive it more. Take it for a longer trip. 100 miles or more and get it thoroughly warmed up.

I am running Shell Rotella oil with one quart of automatic transmission fluid. I've been doing some in town driving as well as some open road, varying the speed. The sticking valves seem to be freed up, as well as some sticky rings. Packards don't do well when you start them, run them for a few minutes and put them away. That produces lots of water vapor, which can easily lead to rusting around the valve stems. I'll run that mix for about a week, then drain it and fill with regular Rotella. A little bit of Marvel Mystery Oil in the oil and gas is a good preventative in my mind. There was a device that used engine vacuum to squirt a little in the carb each time you shut off the engine. I would like to find one.

If one valve sticks chronically, other possibilities are a weak valve spring or, if a recent valve job was done, insufficient clearance between the stem and guide. But first and foremost I'd agree with others, engine run infrequently and not long enough to get fully warm are prone to sluggish valve response.

Thanks for all the prompt responses and ideas.
Engine was built 20 years ago.
Since we are retired and travel a lot, our cars sit for extended periods sometime....hard to avoid that situation.

I have heard a lot of folks swear by MMO...and some claim it is just transmission fluid....who knows for sure?!?!...but will heed your advice and report back on results...

Thanks

Bob

Hi bujak:

The big risk is the valve sticking partially open and damaging the cam rollers.

With a worn motor your problem is the result of corroded/pitted stems and guides. So given how expensive Packard motors are I would consider replacing the valves and guides.

Before new parts were available the old timers used to clean the guides and polish the stems. So you can try that as well.

Also, heavy oils don't mist as well as lighter oils. The manual specifies 20w for your car up to 85F so you can try 10w-30 if the motor is using detergent. Marvel oil has the same effect. Note as well that Packard explicitly stated using the next lighter grade over the next heavier grade. As long as you are not running the car over 45-50mph and not lugging the lighter grade should not be causing problems at the rod bearings.

Hope this helps.

Good advice, Tim. A particularly good way to clean guides, assuming they are just gummed and don't need replacement, is to use a brass pistol or rifle bore brush of appropriate diameter (about 38 caliber) soaked in lacquer thinner and of course using an absorbent cloth below the guide to prevent the solvent and goop from entering the engine.

Also, though I've never done it myself nor found it necessary, Packard's recommendation for sticking guides on the 1938 junior engines might be worthy of consideration.

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I've had a chronic problem with sticking exh valves on a 88 Ranger 2.0 for over 4or 5 years now. With out boring everyone with a lot of detailss i will simply say that it is FACT that the valves are sticking.und the stem near the vlave head.

IT IS A very LOW speed operation engine, rarely over 35 mph.

I've found that the STP Gas Treatment will clear up the problem very fast within about 50 miles of operation or LESS.

The problem WILL return if i miss more than one gas tank fill up and treatment
REMEBER, this is a very low speed operation engine andd is operated often with out adequate warm up and mostly very short run times.

It is not practicle for me operate the engine in other fashion for reasons i won't go into.

HOWEVER, the STP Gas TReatment is rather EXPENSIVE. It alsso SMELLS just like Diesel or coal oil.
SO, i tried diesel fueel (assuming detergents in diesel fueel = detergents in STP Gas Treatment. No significant success with the diesel fuel addition to the gas tank.

SO:
Just exactly what ingredients does the STP have that the pump Diesel fueel does not have????
OR:
If we buy the STP ingredients seperatly it would be alot cheaper and more convenient to deal with this sticking valve problem.

I would suggest that the next time it sticks you remove the plug and squirt some Lucas Injector Cleaner onto the stem of the valve so it flows down to the valve guide. Let it sit for 5 to 10 minutes and restart. Or why not remove the plug and turn the engine over (without it starting e.g. by disconnecting the coil wire)until the exhaust valve for #7 opens and then squirt some injector cleaner onto the valve stem. Let it sit overnight and give it a try.

My reasoning for using the injector cleaner is that I feel it is better at attacking carbon type deposits. I have always been a proponent of using ATF to clean out the insides of an engine as ATF's are very high in detergents.

Good Luck and keep us advised.

Bujak, with your symptoms I'd suggest a weak valve spring as a likely suspect. If you do pull the head and change the spring, I'd also polish the valve stem and run the proper size reamer thru the guide. Of course you'd check all the other guides and springs.

A good technique for cleaning guides is an appropriate size brass rifle bore brush and lacquer thinner, as noted previously.