Spark plug hole repair 2003 Lincoln Town Car


#3 spark plug blew out of engine block as if threads stripped. How do I  perform the spark plug hole repair to get a spark plug back into hole securely?


You will need a spark plug hole repair kit. The kit needs to be specifically designed to work with deep hole aluminum heads. After doing a little research, I picked this one because it was the cheapest one that had all of the proper extensions. I have left you with some useful tips below to keep in mind when repairing the spark plug hole.

Spark Plug Hole Repair Kit

Ford spark plug hole repair kit

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  • Replaces stripped spark plug threads on aluminum heads with 14 millimeter spark plugs
  • Installs a new spark plug thread insert in original thread location
  • Repairs original spark plug hole


A couple of spark plug hole repair tips, I would like to pass on:
1) This kit is not supposed to work on Triton engines with double overhead valves. Check your engine.

2) While everyone says to use grease on the tap to catch the aluminum shavings, I used Vaseline because I didn’t have any grease, it worked just as well, is less messy, and is more transparent (I like to be able to see what’s coming out).

3) If working on a Ford, don’t forget to order a new ignition coil and spark plug for that cylinder because the old ones have obviously been destroyed. You will also need to pick up some high temp tread locker for the new insert.

4) Before tapping, I made sure the piston wasn’t at the top of the cylinder (I don’t know if it would have mattered, but just to be safe). I made one long drinking straw out of two and poked it down the hole to get an idea of where the piston was.

5) Before starting, get one of those telescoping magnetic pick-up tools. You can easily remove the old spark plug and anything else from the deep hole while you’re working… it’s a headache saver.

6) As someone else mentioned, after you tap the engine cylinder head spark plug hole, crank it for a second to blow out any little pieces of trash / shavings that may have fallen into the cylinder. I did this so I wouldn’t have to rig up a Shop Vac with a little tube.

7) I wasn’t able to use the wedging tool to lock in the insert better because I had no swinging room for my hammer. I don’t think this will be an issue. Someone even suggested that it might be best not to since we are dealing with an aluminum head.


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