I bought a 03 F450. The only info the owner could give me was that he had it checked out and they told him the turbo come apart and locked the engine up. He couldnt tell me any thing else. Well I have started tearing it down (with some help from you fellows) and I got the turbo off and it looks like a pretty new one with a rebuilt sticker on it. No fins busted or missing, that I could see and spins over freely with no bearing noise. Finally was able to get a wrench on crank, I can turn it backwards, but when I go back the other way it stops. Dont want to damage any thing. This indicates to me at least that crank has not locked up. Started taking heads off, have one almost off. Someone told me something about a bolt or something come out of the engine, cam maybe and locking the engine up. I gues that I've got it this far torn down, I'll go ahead and remove both heads. Any thoughts if I dont find something in cyl head.

 

you went clockwise or counterclock wise?

 

I believe that I turned it counter clock wise, about 1/2 turn. Just enough to see that the crank wasnt locked up, then when I went cw. it turned about 1/2 turn and felt like it was hitting something. I imagine, what ever it is, if it is in the combustion chamber, the block will be shot, probably head too. I am still going to spend some time and try and get the heads off and go from there.

 

get the heads off and try it. turn it clockwise. could have been a bent rod or several but doubt it.

 

Might want to drop the inspection cover and look at the flywheel and torque converter bolt areas.

 

forgot about that. good info rusty. take the tranny off and unbolt the tc. i didnt replace my tc right when i did my brothers truck (just like what you are doing) and it wouldnt turn over. took the tranny back off and it turned like a champ

 

The motor could be hydro locked from a blown head-gasket or ruptured EGR cooler.

 

I also agree, and would remove the glow plugs 1st and try turning over.

 

Well, I think I am going to have change my plan of attack. It has a std. trans, so I dont think any converter bolts are hitting. Got left head off and every thing looks fine. I guess I didnt turn the crank back as far as I thought. Tried it again and would rotate backward about 2", then felt like it was hitting something, so I dont think it would be hydrolocked. I think I am just going to bite the bullet and pull the engine as it is a bite leaning over it trying to work on the heads. If I had know what I know now, I think I would have pulled it in the first place, just hopeing that it would be a head gasket. I will repost in a week or so. I am working on this job like Johnny Cash built his car he sung about, "one piece at a time". Still cant think it would be a rod or crank bearing locked as when it turns, it turns easy, till I felt it stop by hitting a solid object. Any one have any ideas?

 

I hear ya on the "One Piece at a Time" Haha. It is good that you don't have a time crunch though. Being in a hurry to get your transportation back on the road isn't fun. What you are describing could be a lot of things. If you keep pulling it down you will eventually get to the problem. If you're turning the crank and you bump the place where it stops, does it stop sharply and make a "clunk" sound? Maybe with a helper you could investigate where the noise comes from. top, bottom, front, rear of the engine. Might get a clue from that. Top-maybe somthing in the cylinder(s) riding on top the piston and hitting the head at the top of it's stroke. Bottom contact between a rod or crank throws with the block or somthing that ain't supposed to be in there. Front- broken timing chain (think it has one, haven't had mine apart) or somthing came apart. Back- somthing came apart or broken in the clutch/flywheel. It would be a drag to get the engine out and the other head off and find a problem with the timing chain (or whatever drives the cam). If the engine had a sudden stoppage while it was running, I seriously doubt bumping into it going to hurt anything. If there's no metallic noise, I would think water in the cylinder and pull the glow plugs or injectors on the remaining head as weekendwarrior suggested. As a matter of fact, doing this first may make the engine a little easier to turn at the crank even if water is not the issue. Good luck man, and keep us posted!

 

Reminds me of a thread where 3 shops told this guy his motor was shot. And it turns out it was the pulley on the ac compressor. It was locked up due to a bad bearing. Changed it out and it fired right up! That truck would only turn backwards as well.

 

It could have been but the coolant would have seeped past the rings at this point.