willysmjeeps.com

Guys:

I had my engine overhauled 7-8 years ago. (CJ2a engine in an M-38 jeep). Been sitting in a garage since (a few months outside, but with plugs in). I'm 'bout ready to fire her up and I learned today I've got a stuck exhaust valve on the front cylinder. Valve moves a little, but won't close. Any ideas how to free-up that sucker short of pulling the head?

Thanks,

Jordan

Get some Freeze Off from local auto parts store. I get it at OReilly.
Great stuff. Have used it to unstick many things and I am always amazed.
Spray it thru the spark plug hole on the valve stem.
John

So, hit the valve stem with the freeze off and then crank the engine and see if she breaks loose? Will try it. Thanks for the idea. Never ever heard of freeze off.

G740:

Can I access the valve stem through the spark plug hole? Doesn't seem like I can reach it from the spark plug hole. Am I right?

Jordan

Jordan,

In some bores the plug is over one valve and in others it is over a different valve. Either way you can get the penetrating fluid into the opening at the valve seat if the valve is off it's seat when you spray. Sometimes you will have a straight shot for the spray straw and sometimes you will have to bend the straw a bit and sometimes you can bounce the spray off the edge of the combustion chamber towards the manifolds.

Thanks guys. Much appreciated. Gonna soak her in some Kroil (or maybe ATF cut with 50% Acetone---they say that's the bomb for penetrant), then hit 'er with Freeze-Off and turn the crank. See if she breaks lose.

Jordan

A pain, but you can remove the intake/exhaust manifold and get right at it. Do that id the other methods don't work. Good luck, hope it frees. Since it moves a little, I think you will win. John

Can valve seats be recut while the engine sits in the jeep? I've got rust damage to two seats which will prolly require recutting the seats. The others can prolly be lapped. Valve man is coming Friday for a look-see. I sure as heck hope I don't have to pull the motor. (Left her in the rain once with loose plugs in the cylinders and water leaked in. My fault.)

There are portable pilot type seat grinders but you may have a clearance problem for that tool with the rear seats.

That's what I am afraid of. We'll see.

In the 1st post you were searching ways to free a stuck valve
w/o pulling the head.

I'm guessing that if you're looking at damaged valve seats you've
gone ahead and pulled the head .

Did you get the stuck valve freed??

Yes. We pulled the head and all valves and recut all seats and also dressed the valves. Hope to have her reassembled by tomorrow.

Thanks for all the help here.

Jordan