03 Ford Expedition. Spark plug blew out. changed coil pack and plug now wont start.
 

The other day, as I was driving home I heard a funny sound then the truck started sounding like a Harley. I pulled over. A guy working on the telephone lines came up and told me he knew what the sound was. I had blown a plug.

So, I drove it home, parked it. Got my father whos a mechanic to help me check it out. We both saw that the one all the way in the back on the passenger side was the one that blew out. I thought I had to get the thread fixed, turns out I didn't. At least thats what my father declared after looking at the spark plug and seeing no sign of it being stripped. Only that it could have been loose and finally just shot out.

So, we got a new plug, new coil pack. My father put the spark plug in with no problems. Put the coil pack on. To get to the coil pack however, we did take the coolant hose and the silver fuel bar off. Everything goes back on. I get in to start....and nothing.

It actually does this thing where it doesn't do a full crank. It's like a half crank. First thing we thought was, battery might be dead. We try jumping it, and same results. Half crank.

My father then says it might be what he hopes it isn't. I need a new cylinder head!

Next day I call a local auto shop in town. Tell them my problems. They say it could be the starter, or the battery and that we should get both tested. Today I went out to try and start it. Same thing, only this time I noticed the needles jump when I had the key turned over longer. I've only seen them jump like that when there was an issue with the battery.

At this point I'm stumped. I don't want to get it towed to the auto shop so they can give a full on analysis of it, and tell me something that I didn't have to pay them for. But I'm out of DIY options and ideas.

We tried taking off the starter to have it checked for free at Autozone. Couldn't get it off. That's one tight @#$ spot. I can get the battery off to have it checked by autozone. I just thought I'd come here in the meantime to get some idea of whats going on.

Can anyone give me some advice?

Is it possible you spilled coolant or fuel in the open hole and have a hydro locked engine ?

Couldn't have. We would have seen it. The coolant hose gushed coolant out when it was removed but that was before we got to the coil pack and it was moved out of the way so not to mess anything up.

I'd check the battery, battery terminals, and battery cables first. The easiest thing to do and the highest probability of the solution. Starter next.

That's exactly what I was going to do as soon as I get off work. Luckily I have the next 2 days off so I can troubleshoot and hopefully solve my issues.

Just had the battery tested. Its showing that its good via autozone.

So is it running now after the plug and cp issue with it half cranking?
No reason to think one issue has anything to do with the other. Was it slow to start before the fix?
Pretty rare for a starter motor to go bad, "slowing down." Usually the bendix goes bad and you get a clicking when turning the key.
I would still clean the terminals and ensure your cables aren't bad.
No reason to believe the head has anything to do with it also.

It was running before we changed anything. It would crank a little longer than usual but would run and stutter and make the loud Harley noise. It actually wouldn't turn over at one point but eventually did start before we changed anything. Nevertheless, it still did more than what its doing now. Looking at the terminals there was some white crust (I know the proper word for it but for the life of me I cant remember it right now. Thank the graveyard shift for lack of sleep and brain productivity. )

I'll clean the terminals and try to start the truck in a bit. Looking at all the connections I can't see anything out of place.

This happened to me one time when I changed all the plugs and had to remove the wiring on the passenger side to get to that sparkplugs. You could have knocked something out of its place.

What did you do to fix it? Go back through everything and reconnect it? I think that's what needs to happen.

Can you get a socket and ratchet on the bolt in the middle of the front pulley? If so see if you can turn the engine. This will let you know if it's a locked engine or if the starter just isn't cutting it anymore.