Stuck Valve??

[jrvariel48]

Hi,
I noticed a stuck valve when I finished a highway trip yesterday.
I did a compression check because the motor sounded funny & the drivers side exhaust was pushing cold air! I found the intake valve in the #6 cylinder is sticking open. The motor is a 1946 59. The car is a 1935 5 window coupe.
The valve moves up & down a little when I crank it over, but doesn't seat all the way down. There's about a 1/4" gap.
Is this the sign of something other than a stuck valve?
I run an Ampco bottle with MMO & also have MMO in the oil. I had a valve sticking on the passenger side, hence the MMO.
This was the first trip I took on the highway since I put the car together.
About ten miles at 60 m.p.h. It ran fine(I think) until I pulled in the driveway.
I got the motor from a friend of a friend, etc, etc, so I don't know much about it. I was told it was rebuilt, but I don't know when or with what parts.
I did replace the water pumps with a pair of Skip Haney's, which are great by the way, and I noticed the block behind the pumps was very, very clean. I tried shooting some Seafoam & PB Blaster in there over night, but no change. From what I've read here, the best thing to do seems to pull the head & try to free it up or pull the intake for a closer look. Both would be a bummer as I just finish putting the car together. Not a big deal though.
Any help would be greatly appreciated.
Joe

[37 Coupe]

I know you have said you are running an Ampco MMO jug but before you tear into engine give it a good dose of MMO while it is running through the carb. This was the only way it worked for me when my new 59AB had a valve or two hanging up. I put MMO in the gas tank not the oil.

[B-O-B]

I also run MMO & seafoam in the tank. Starts right up after setting for the winter.
I had a 223 6 in a f-5 truck that had stuck valves & I ran a qt or so of tranny thru the carb. Freed the vales up & continued to run seafoam in the gas tank,no more stuck valves. Smoked a lot with the tranny oil but didn't have a bugs for a spell.

[VeryTangled]

Hi Everyone, I actually read the MMO directions last week, just for grins. It says to use it in place of 20% of the oil (ex. one qt MMO to four qts oil), and to add 1/4 cup (4 oz) to each 10 gallons of fuel, the jug has markings on it to help. I'm adding it to the fuel but haven't tried it in the oil yet. Not sure about that idea.

Not saying the idea to put it down the carb is bad at all, in fact I can't see any reason not to try it. Just relaying what is on the package, for what it's worth. The directions gave me the kind of feeling that I get about 'wonder drugs' that will cure all your ills. Many claims, not so much proof. Still, I'm using it in the fuel.

-VT/JeffH

[37 Coupe]

I didn't mean to run a whole bottle as such down the carb,it wouldn't run long anyway but you drizzle some down the carb while engine is running. Take it out and run her up to speed and see if it doesn't smooth out.

[JWL]

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If it doesn't respond to liquid repair methods, pull the intake manifold first. It is easier to remove and replace and the gasket is less expensive. Then try to free it up. You'll be able to see any screws or nuts that might be in the intake port or a loose valve seat ring.

[jrvariel48]

Thank you to all that responded!
I will try the MMO in the carb & hopefully that'll work before I take off the intake. I'll let you know the results.
Thanks again,
Joe

[oldford2]

How do you know the valve is stuck open 1/4"? In any event listen to JWL. Pull the intake and check that valve and the others. Not a big job. Get a new gasket in the mail while you are checking it out. 50/50 chance of reusing the old one. If it is sticking pop out that assembly and clean the stem. My Ampco/MMO seems to work fine. No sticking valves (yet).
John

[jrvariel48]

Originally Posted by oldford2

How do you know the valve is stuck open 1/4"? In any event listen to JWL. Pull the intake and check that valve and the others. Not a big job. Get a new gasket in the mail while you are checking it out. 50/50 chance of reusing the old one. If it is sticking pop out that assembly and clean the stem. My Ampco/MMO seems to work fine. No sticking valves (yet).
John

John,
I can see the valve through the plug hole. It moves up & down a little but remains open about 1/4".
Is there any special gaskets I should be looking at for intake or heads?
Thanks,
Joe

[Mart]

I'd be tempted to lean on the valve with a screwdriver and see if it will close with a little more pressure than the valve spring can exert. You may be able to (obviously with care) press on the screwdriver while cranking it over, and spraying some wd40 or something all under the valve. I haven't tried it, but you might even be able to press on the valve with the engine running at a slow idle.

It just needs a bit of persuasion to get moving. While it is not moving (ok, just a bit,) it is not being lubed by the oil dosing you are giving it.

Mart.

[Terry,OH]

Remove spark plug and squirt MMO down the stem of the open valve turn the engine over by hand and you should be able to gently tap the valve back to the seat repeat over and over until the valve returns to it's seat on it's own. If the valve doesn't return with gentle taps or moves very easy to the seat once tapped you have a bigger problem and it has to come apart (maybe a broken spring or such).

[Walt Dupont--Me.]

A little tip on the intake gasket. When installing coat the gasket good with greas on both sides. You usually can remove the intake 2-3 time and use the same gasket. Walt

[Mike51Merc]

Could be valve, could be lifter. Pull the intake first, then possibly the head. A "recent rebuild" shouldn't be gummy inside. You might have spit out a valve seat. I just fixed one on my buddy's engine last Saturday (again).

Has the engine made any clinking or tapping sounds recently?

[jrvariel48]

Originally Posted by Walt Dupont--Me.

A little tip on the intake gasket. When installing coat the gasket good with greas on both sides. You usually can remove the intake 2-3 time and use the same gasket. Walt

I will do that! Thank you Walt!

Originally Posted by Mike51Merc

Could be valve, could be lifter. Pull the intake first, then possibly the head. A "recent rebuild" shouldn't be gummy inside. You might have spit out a valve seat. I just fixed one on my buddy's engine last Saturday (again).

Has the engine made any clinking or tapping sounds recently?

Kind of hard to tell. I had a very short temporary exhaust on so it was loud.
I had an exhaust system put on a few days ago. I can definitely hear the valves tappin' away, but i didn't think it was extra loud.

[rotorwrench]

Worst case scenario: Looking in the lifter galley should tell if there's a problem with a follower. If a guy has an intake valve that won't quit sticking, you can rig a bar to work the valve while the intake is off. You can then put MMO in a squirt type oil can and squirt a shot of MMO onto the intake valve stem through the port for that cylinder then work the valve up & down till it frees up. If it doesn't then it would be time to pull the head and then the valve assembly out & find out why it's sticking.

[jrvariel48]

Well I'm believer in Marvel Mystery Oil!!
I shot some MMO down into the valve, put the plugs back in and started it up.
Poured some MMO down the carb while running and not 30 seconds later the valve freed up!!
UNBELIEVABLE!
Let's just hope it stays that way!
Thanks for all the input from everyone!
This is truly an amazing place.
Joe

[Mart]

Ace!

Mart.

[G.M.]

Originally Posted by jrvariel48

Well I'm believer in Marvel Mystery Oil!!
I shot some MMO down into the valve, put the plugs back in and started it up.
Poured some MMO down the carb while running and not 30 seconds later the valve freed up!!
UNBELIEVABLE!
Let's just hope it stays that way!
Thanks for all the input from everyone!
This is truly an amazing place.
Joe

Put it in every tank full of fuel and you won't have any more sticky valves. This new gas puts a thin white resin like film on the valve stems,
this is what causes them to stick. G.M.

[41ford1]

Originally Posted by VeryTangled

Hi Everyone, I actually read the MMO directions last week, just for grins.
VT/JeffH

You know you are only supposed to do that when all else fails - "RTFM". You did that just for grins now something's going to break. You have jinkst yourself.

Originally Posted by jrvariel48

Well I'm believer in Marvel Mystery Oil!!
I shot some MMO down into the valve, put the plugs back in and started it up.
Poured some MMO down the carb while running and not 30 seconds later the valve freed up!!
UNBELIEVABLE!
Let's just hope it stays that way!
Thanks for all the input from everyone!
This is truly an amazing place.
Joe

Do like GM says. Since you are running an AMPCO oiler increase the dose or add it to the gas for a while. With the engine being a recent rebuild tight clearances of the valve to guide, light spring pressures and the gas available today all are factors for sticky valves. The MMO will keep you motoring on.