NGK spark plugs breaking.

Heywodja said

are you using a socket with the rubber washer inside that grabs the plug so it won't fall out while removing/installing?

If you are not, it doesn't take much to have the socket misaligned with the plug which causes contact with the metal socket to the ceramic insulator causing it to break.


Spark Plug Failure #1 Socket Strike! | The Spark Plug Manual

Click to expand...

I think you just solved my problem. After reading your post, I went out and inspected my socket set. Sure enough, the foam insulator in my spark plug socket was missing. Somewhere along the line the foam insert fell out and I missed putting it back in. This was about the time I started breaking spark plugs. Will go out and get a correct socket with the foam insert in it. Thanks for a good catch!