Seized both ways 5.4 3v

jkplusplus

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I've got an 05 f250 with a 5.4 3v. Was pulling a trailer and had the cel start flashing / truck started running rough. Had happened a couple of times in the past when pulling, usually flashed for about a minute then went back to normal. This time that didn't happen. Started running real rough, losing acceleration. Pulled to the shoulder and felt the wheels lock temporarily, then rolled to a stop and just clunked when trying to start. Removed the spark plugs after towing it home. The electrode tip was missing on one plug, all the rest were unremarkable. The tip is small enough that I would expect it to get expelled through the exhaust, but it might be possible it's stuck.

I figured it was junk, so I tried starting it occasionally. Every now and then it'll spin real slow for a 1/4 turn and then clunk. Can't get it to spin manually in either direction. I saw a post on here where another fella had a similar issue where it wouldn't spin either way, and in that case it was the timing guide stuck in the sprocket. Getting ready to pull the valve and front covers off.

So a couple of questions:

1.) Do you think it's a broken timing guide, a wedged spark electrode, or other.

2.) Given the severity of how it stalled, even if it's the timing guide wedged in there it could also have more damage elsewhere. Would you spend the money on the OEM timing kit + HV oil pump, or would you go cheap so you don't spend $1000+ on an almost 20yr old truck only to have it still be junk when you put it back together.

Any guidance and opinions are deeply appreciated.
 

Black dawg

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I would bet something knocked that electrode off. At this point I would be pulling the engine. Maybe it can be saved, but buy your description I would bet not.

If you have a way to get the cab off, it is a very easy engine r and r.
 

Jesus Freak

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Maybe start looking for another engine. They're proud of those 5.4s though. I had a 99 F250 that the engine seized up on. I ended up putting a 4.6 in it with a plenum off of a 03 F150! The throttle tube thingy with the TPS and such bolted on the plenum and everything lined up. I called it my w*e*i*ner truck.
 

jkplusplus

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That's an interesting point about the electrode. I could probably rig up an A frame to pull the cab, but that's more than I'd really care to put into it. Seems like I can get the valve and front covers off fairly easily, if it's a guide then I can at least clear it and then see what happens when I try to spin the motor. If it's not that than I think this truck has a date with the junkyard.
 

Jesus Freak

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If it's not that than I think this truck has a date with the junkyard.
What sucks is, that is what these trucks were designed for: to just throw away instead of repairing. It's definitely a legitimate option, but it sure is nice to squeeze as much life out of a truck as possible.
 

jkplusplus

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What sucks is, that is what these trucks were designed for: to just throw away instead of repairing. It's definitely a legitimate option, but it sure is nice to squeeze as much life out of a truck as possible.
Yeah I totally agree. It's a good truck, but not worth dumping a 6k motor in. Hopefully there's salvation waiting in the front cover. And that's the struggle of whether to spend on OEM or throw another disposable timing kit / oil pump in there. For the cost of the kit I could almost buy another disposable truck and get a year or two out of it.
 

jkplusplus

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Well I finally got around to pulling the valve covers and front cover off. The passenger side upper timing guide was busted, with a couple of big chunks tied up on the chains. Cleared those, and then tried spinning the motor by hand again and still nothing, jammed in both directions. I ended up buying an 06 f250 with the same 5.4 3v, so I'm thinking this one is just going to have to be a parts truck from now on. It's a shame, it was a nice riding truck for a while there.
 

Jesus Freak

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Well I finally got around to pulling the valve covers and front cover off. The passenger side upper timing guide was busted, with a couple of big chunks tied up on the chains. Cleared those, and then tried spinning the motor by hand again and still nothing, jammed in both directions. I ended up buying an 06 f250 with the same 5.4 3v, so I'm thinking this one is just going to have to be a parts truck from now on. It's a shame, it was a nice riding truck for a while there.
Thanks for finishing the story!

And yeah don't throw the 05 away yet, maybe a craigslist find or a wrecked, parting out situation will show up.
 
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