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- - V10 Spark Plugs (https://www.ford-trucks.com/forums/102008-v10-spark-plugs.html)

I have a 1999 F250 (V10) with 103,000 miles on it. The spark plug in #4 cylinder has come out of the head and the threads are damaged. Has anyone heard of this happening or does anyone have any theories on how this could happen? All 10 plugs were replaced around 68,000 miles by the dealership where I bought the truck. The servicemen at the dealership have never seen anything like this and think that the plug had to have been blown out or that something got into the combustion chamber that knocked the plug out. I don't see how this could happen and the top of the piston (viewed with a bore scope) doesn't appear to be damaged. Any help would be appreciated considering my options are to pull the head and try to repair or replace at around $4000 or put in a remanufatured motor at around $5500.

Welcome to FTE!

It is unfortunant that you had to find us V10ers when you got a problem... :(

I moved this down here in the V10 forum because some feel that there is a lack of traffic down here. (I agree).

Plus while you're down here you'll see that this has been discussed many, many times. It is not "common" but it is a "common" complaint on the board. See how others have dealt with it. I'm sure those who have had the problem wouldn't mind you Pirvate Messaging them to see if the can help you out in any way. (Well...other than $$ :D )

Can you install a heli-coil?:(

Heli coil? Is that to repair the threads? Thanks, I will scroll down to see the other cases. I'm not thrilled to hear that this is not uncommon. This was my first experience with a Ford truck after being a Chevy man for years.

Monsta, I haven't come across the other topics. Can you tell me where to search. Thanks.

I found this on another site from a Ford Tech:

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Icon 1 posted October 18, 2002 09:40 PM -
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Abarth, the most likely cause in your particular problem would be the heater core tube that is positioned directly over the #4 cylinder, (last one on passenger side), have you ever had the coil for that cylinder replaced? .. My guess is yes, because of a missfire problem.

What happens is the coolant seeps from the pipe down onto the coil and shorts the coil, but does not end their, the coolant then seeps down in and around the plug itself, and sets up a basin of collection for the coolant.

Now lets mix ethyleneglycol with aluminum head and steel spark plug, and what do we get from this magical combination?. CORROSSION of the weakest link, being the aluminum threads of the spark plug hole in the head.

Takes a while for this extreme condition to occur due to the sealing surface of the plug to head, but can and has happened.

Don't take rocket science to figure it out, just a little knowledge in metalergy.

Ford knows this to be a problem, but as of yet, short of a class action lawsuit, the problem remains the same.

I have noted that they have rerouted those heater core pipes, but that's not much consolation to those who still have the original setup.

Should be a recall on them but they have not written one for this OBVIOUS design flaw.

Good luck, and wish you the best in fighting corporate policy, We at FRT have been trying for a very long time. [Roll Eyes]

*Disclaimer*
This has been a commentary of my own observations, and should not be construed otherwise. --------------------

My truck just turned over to 70,000 miles, so I changed my plugs this past weekend. Sure enough, the 4th one back on the passenger side had some (not much) corrosion on it. I still have the old plugs and will try to post a photo tonight. The other 9 plugs had no corrosion.

I installed new Motorcraft platinum plugs and noticed a small increase with the "Seat of the pants" dyno. It took me about 3 hours to get them all changed. Not as bad as I had expected. Make sure you have an assortment of extensions and universal joints!!! When you get to the plugs towards the firewall, you'll understand why...

Don't think that these plugs can go 100,000 miles. Mine needed to be changed.

Best regards,

Jeff

sure makes me nervous about changing my plugs... may have to try it tomorrow night ;)

Picture is now up on my web page. Click on the link at the bottom of this post and then click on "New Spark Plugs."

Best regards,

Jeff