I broke a spark plug off while changing them and when looking in the hole with my camera saw there was still porcelain left from the plug, couldn’t get anything in there to fit to break it out so i called my co worker who told me to spray penetrating oil in it then start the car and wait until the porcelain blows out of the spark plug hole and turn the car off immediately, then use an extractor tool to get the rest of the plug out. so i did that and it the car is running fine now just wondering if anyone else has done this or if i’ve done any damage because it seemed dodgy the way it was done.

  • Welcome to Motor Vehicle Maintenance & Repair! Commented May 5, 2023 at 9:44

2 Answers 2


If your are saying a bit of porcelain dropped inside the cylinder, then what you did doesn’t sound like a good idea, but it does sound like you got away with it. The porcelain could easily have scratched the cylinder wall, damaged the piston rings or done even more damage.

I think I would have first tried attaching a small pipe to a vacuum cleaner and inserted the pipe through the spark plug hole to vacuum out the debris.


If you believe you retrieved the entire sparkplug, you were able to fit a new spark plug, and the engine is now running correctly, more than likely there has been minimal to no damage done to your Pilot. You'd have to fully pull the engine apart and inspect it to know for sure. In this case I'd suggest you should live by my old saying: If it ain't broke, don't fix it.

As far as how you got it fixed, I would have not thought to do that, however, it doesn't mean it did any harm. I say this because your explanation isn't very clear as to what exactly was left of the sparkplug. The main idea was to get it out of the head so you could fit a new one. As long as it went out instead of in (meaning the cylinder), you should be in good shape.

  • I would have never have thought to do it that way either my co worker said he’s done it plenty of times, when there’s still porcelain left on a broken spark plug and it’s not accessible to get something in there to chip away at it and break it, we sat there for 20 minutes with the car misfiring until we heard a pop and the rest of the porcelain shot out of the spark plug hole and onto the ground.
    – Gaege
    Commented May 6, 2023 at 10:06

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