Questions about unsticking a motor UPDATE

[FordTruck]

The 300 I put in my 72 has been sitting unstarted for about 3 years and I was wondering if any of you guys have any tricks on how get it freed up. It'll turn about maby a quarter of a turn then stops. I was also wondering if there is any way to tell if its just the piston sized up because of no oil or if a valve is sticking or something like that. I tried kerosene,brake fluid and WD-40 but no luck. Any ideas?? Also I guess I should say I know the motor has never had any hard use since it was in my dads work van that he hardly ever drove and did run but like i said its probably been 3 years or so.

[fordman]

if it will turn a little you are in better shape than if it wouldn't turn at all. someone told me to put diesel in the cylinders to free up my pistons. since yours will turn a little you can also turn it one way and thne back the other and try and work it back and forth. it is probably just the rings stuck to the cylinders.

[lee_ford]

It'll turn about maby a quarter of a turn then stops.

Are you saying each time you crank it, the motor only turns a quarter way around?
Or are you saying you can rotate the crank back and forth a quarter turn? The answer will make a BIG difference on where to send you looking for the problem.

If you are saying the motor cranks only a quarter turn each time it is engaged, then you have either a bad battery, cable connection, solenoid or starter.

If you are talking about turning the motor back and forth…

I was also wondering if there is any way to tell if its just the piston sized up...

A ring stuck to the cylinder wall will only let the crank turn a very little bit. Like maybe a half a degree or less. Picture the slack in the ring grooves.

…or if a valve is sticking…

One valve stuck OPEN will let the crank turn about 7/8th turn back and forth.
One valve stuck CLOSED will let you turn the crank back and forth about 1 3/4 turns.

More than one valve stuck open or closed could result in a quarter turn, depending on which valves are stuck.

Having said all that, I hope you meant it only cranks a quarter turn each time you hit the starter.

Lee

[papabug71]

You could use a crapload of PB blaster. Its always worked for me in the past on some really stuck stuff.

I think you can buy it by the jug at Lowes or Home Depot.

[mrsnicks]

I've always heard you should put 2oz of Marvel Mystery Oil in each cylinder. Pull out the spark plugs, use a turkey baster and squirt it in. Put the plugs back in and let it sit for a day or 2.

If none of these work you'll have to pull the head off and take scotch pad to the cylinder walls if it's corrosion, or pull the head to see what's really going on.


Patrick

[fordwannabe]

I have had some luck with the diesel fuel in the spark plug holes , let it sit for a day or so and then pull it behind another truck to break an engine free. I also tried that for 2 weeks on one engine and finally pulled the pan to discover the connecting rod wedged in the block sideways(OOOPPPPS). Tom

[My427stang]

Did it run when parked?

[FordTruck]

Did it run when parked?

Yep it ran perfect. No weird noises or anything.

[lee_ford]

Did it run when parked?

Yep it ran perfect. No weird noises or anything.

While all the above answers are great for people with a motor which is STUCK, your motor turns.

It'll turn about maby a quarter of a turn then stops.

So, which is it FordTruck? Is it only turning a quarter way around when you crank it or is it only letting you rotate the crank back and forth a quarter turn?

No mater which it is, it is NOT the pistons, rings or ANYTHING that oiling down the cylinders will help. A quarter turn says it is either a bad cranking system or something major inside the motor.

Lee

[My427stang]

I agree.

If it wont turn, try loosening the starter. Sometimes the drive can come apart or get stuck and bind.

[FordTruck]

It'l olny turn about a quarter of turn with a rachet and a braker bar on the crank bolt. It'll go about a quarter one way then stops like its loked up then it'll go back the other way about a quarter then locks again. Everytime I go out there and try it'll move a little bit further. Also I don't have a starter on it because its on my 70 and I still have to run wires for it.

[FordTruck]

Here's where its stuck



Then its free and then here's where it gets stuck again



I took thease turning the motor counter-clockwise with a socket and rachet on the crank bolt.

[rjewkes]

anything in the area the starter would be? if something gets between the flywheel and the bell housing it could have that effect.

[FordTruck]

anything in the area the starter would be? if something gets between the flywheel and the bell housing it could have that effect.

There's just an empty hole where it should be. The olny thing that maby could have gotten in there would be a few mud dobbers but nothing that should lock it up like this.

[rjewkes]

Their nests if they build in there can be pretty strong, would bust apart after a bit i'd think though. The guy who posted about corrossion could be right too. if it sat long enough with no fire the rust coulda built on the cylynder walls.

just a tiny bit of moisture getting in could cuase this in short time. left open they can flash rust over night and lock the pistons up. you may have to pull it appart and clean it up and rebuild it too since you'll be in there.