I recently purchased a 2005 F250SD 4wd with the 5.4. I knew when I purchased it that the engine was locked up. After I got possession I asked the mechanic if he would pull the plugs, which he did and it still would not move. The starter was pulled, the serpentine belt was removed, did find one injector was leaking. The engine will turn backwards as much as you want, but will only turn forward for less than a turn and it does not stop in the same place. The cam phasers were repaired about 30,000 miles ago. before the engine locked up it ran very poorly. the owner let it sit about 30 days and was going to take it to the shop when he discovered it would not turn over. The engine has about 130,000 on it. What would be wrong that the stopping point if different every time? I did read a post one time that a bolt had fallen through a hole in the back of the intake manifold and would wedge itself between the flex plate gear and the transmission housing. Is that a possibility? Will welcome all ideas. thanks

 

I'm suspecting either something fell into the cylinder or a dropped valve. Either way, needs to be inspected to see what the actual issue is or..................

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I appreciate your help. My feeble mind is asking "Why doesn't it stop in the same place?"

 

because the nut, bolt that fell in there is moving slightly interfering with the valve or it is something that is with the valvetrain itself....won't know until you pop the valve covers and also look inside the cylinder

 

I don't think that anything fell down into the cylinder because the condition occurred prior to sparkplug removal. I have a bore scope and will look in each cylinder just in case. I suspect I could also see any valve hanging down. the bolt situation I was referring to would be an external thing. thanks again for your comments and I will post inspection results when completed.

 

That is your best bet checking things out with a bore scope.

Agree with Beechkid that something could have dropped in a cylinder.

Could be that the timing chain broke and is wrapped around the crank??? just a thought.

also, just for grins, if your up for it, unbolt the torque convertor from the fly wheel....if the engine turns over freely....then the problem is in the TC or transmission....yeah that probably is unlikely

 

bore scope turned up clean. could not see anything out of place or anything that shouldn't be there.