1989 GMC Sierra Broken Spark Plug

GMC SIERRA
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BENGIE
  • MEMBER
  • 2 POSTS
Hi, I recently bought a 89 GMC Sierra 4x4 from my uncle. It has 226,000 on it and it runs good, the spark plugs hadnt been changed in 8 years, so i bought some new ones. I got to the second spark plug and it snapped. Just the threaded end of the spark plug is left in it and it is hanging out of the hole a little bit. I dont have any idea how to get it out. I thought i could get a small pair of needlenose pliers and twist the end of the spark plug, the part inside the engine, but i dont have a pair small enough. Any ideas would be greatly appreciated. Ben
May 7, 2006 at 5:57 AM
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BURRBRIAN
  • ✓Experienced Mechanic
  • 158 POSTS
Maybe if you soak it down with w-d40 or liquid wrench or such then carefully drill hole in center you can use a extractor to back out the threaded peice.Short of pulling the head to get to the other end I think this is your best bet.If the plug has been in that long you may have to give it a real good soaking and some time to loosen up, just go slow and easy trying to back it out and you should get there. Best of luck :shock:
May 7, 2006 at 6:33 AM
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BENGIE
  • MEMBER
  • 2 POSTS
my neighbour and i got out the old cutting torch and put low heat on it til the spark plug turned red, then we put an easyout into it and it came right out. We only had one try at it so if n e one reads this just know, u only got one shot if u do this, but it'll work if u do it right.
THANX for the ideas BEN
May 9, 2006 at 2:43 PM
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Suggested Repair

Soak the broken spark plug threads with penetrating oil and allow time to loosen. Carefully drill a centered hole and back the piece out with an extractor, working slowly. If that fails, the cylinder head may need to be removed for access.

Conversation Summary

The owner of a 1989 GMC Sierra broke a spark plug while changing plugs, leaving the threaded portion in the hole. An expert recommended soaking it with penetrating oil, drilling a center hole, and using an extractor, or removing the head if needed. The owner later reported that low heat and an easy-out removed the broken piece on the first attempt.

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