Un-Seizing a Ford 302 5.0L

[scott123456789]

Recently inherited my Wife’s Great Grandfathers ‘69 F100. Even though it sat under a tree sitting for the past 10 years somehow it is Nearly rust free and no Aggie Engineered wiring. The downside is the motor is seized. Patience has never been my strong suit with projects so I’m battling a waiting game.

Monday I pulled all the spark plus and sprayed a healthy dose of PB blaster and poured 3-4oz if Marvel Mystery Oil in each cylinder. Monday I was able to rock the crank an 1/8 a turn or so each day I’ve gone out and it hasn’t improved. I’ve tried to push a bit hard but on the counter clockwise way the balancer bolt is coming lose. Going back the other way I can tighten the bolt but this it just stops.

Do I just need to wait it out longer? Something in the valve train hanging up causing the crank to stop?

Sure someone will say a Coyote motor in it but sure would be cool to get it back in the road just like her great grandfather bought it new from the Ford Dealership in Gordon.

Pic for attention...

[Shu]

If it’s standard put it in gear and pull it.

[bbqfan5909]

Pull the motor and rebuild.

[6.5 shooter]

Might as well just pull it out. Don’t drag it, could break other stuff.

[hgiles]

Sometimes it takes a bit. I’d put some more marvel in it and let it sit a little longer. Work it back and forth until it starts to move a bit. If all else fails, pull the heads and then turn it over.


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[GarGuy]

Gonna have to hone the cylinders anyway. Probably a stick valve holding you up. I would pull the heads and have a look.

[Big Lee]

Pull it and rebuild.

[FLASH_OUTDOORS]

Following along with this!!!


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[BigCohiba]

Keep soaking it for a few days. Put in high gear and rock it back and forth. Mechanical advantage using gearing. Don’t force it. Keep soaking and rocking ...

[texasair]

No way I would modify the motor, Lift it, lower it, put custom wheels on it, or restore it in any way than exactly as original.

Would it help to put a couple of small space heaters under the motor for a few days and get the temp of the engine up a little higher? I don't know. Might be worth a try.

I agree with GarGuy, You may have a stuck valve holding things up.

[Milkfisher]

F100 guy here. Love em’. I have a 72 that’s about to get a crown Vic front end and an axle flip in the back. freshening up the factory 360. Coyote would be great but I don’t need to cruise at 80 on the hiway. I’ll be happy to smoke the tires and cruise at 55 with the windows down.

[Milkfisher]

F100 guy here. Love em’. I have a 72 that’s about to get a crown Vic front end and an axle flip in the back. freshening up the factory 360. Coyote would be great but I don’t need to cruise at 80 on the hiway. I’ll be happy to smoke the tires and cruise at 55 with the windows down.
Great looking truck BTW.

[RifleBowPistol]

With modern fuel, you likely have a bunch of stuck intake valves. I ran into that about 10 years ago. I let a car sit for about a year and a half, then went to start it. It momentarily stopped, then kept cranking. Like it had hydraulic locked. Then it started, made all types of valve train noise. I got in on a trailer, took it to the shop and started checking, found it had two dead cylinders. I found two bent intake pushrods. A buddy had told me, he kept having problems with intake valves sticking, when engines sat for a while. So I took a hammer and tapped on those two intake valves, broke them loose, replaced the pushrods and it ran fine for years afterwards.
I also bought a engine some years ago, from a junk yard, was told it only had about 5,000 miles on it. So I bought it, put it in a truck, then found it was basically locked up, would only turn about 1/8 of a turn, each direction. I pulled the engine, then found that all of the cylinders were full of carbon, that had broken loose. The carbon was keeping the pistons from coming up to the top. Basically there was about 1/2" deep carbon on the tops off all 8 pistons, looked like dirt. I took the engine back to the junk yard and told the guy what I found. He said he knew the engine had low miles and should not be extremely carboned up like I found. Then he informed me the truck was from Mexico. The fuel they have down there is garbage. The carbon that had built up in the cylinders, all broke loose and fell down on top of the pistons, looked just like someone had picked up a bunch of black dirt off the ground and put a 1/2" deep layer on top of each piston. The carbon would not compress, when the pistons came up near the top. A lot of work for nothing. Probably not what you are dealing with, maybe something along the lines of something in the cylinders on top of the pistons. I would still put my money on seized intake valves.

If the engine is locked up because of rusted piston rings, you don't want to do anything with it other than rebuilt it. Another possibility is a locked up oil pump. If that is the case, you would need to pull the pan, replace the pump and pickup. The old valve stem seals are know to get hard, break up in pieces, then wind up in the oil pan and get sucked into the oil pump and lock it up.

I would be investigating why the engine is not turning over and not just trying to get it to spin and start. If it is locked up, there is something in the engine that probably needs some form of attention, likely replacement.

[RifleBowPistol]

If you give up on the truck and it happens to be a short bed truck. I might be interested in it. I bought a 69 short bed for my daughter, the bed has a bit more rust than we were expecting.

[scott123456789]

Does it make sense if my issue is rusty cylinders to have the small amount of movement then lock up completely? Seems like the rust would have been sitting right above the cylinder and not allowed movement?

Everything I read just said pull the spark plugs throw the Marvel in and you should be good to go. I didn’t do anything for the valve train. Can I tell much from pulling the valve covers and inspecting rockers or do the heads need to be pulled?