Not long ago, one of my shop mates salvaged a junkyard engine. The only problem found was that one spark plug hole was cross-threaded. The labor cost to pull the head and repair it with a hardened ...

Occasionally, spark plug threads are ruined by being stripped or burned out. When this happens, a product like these Phillips locking inserts comes in mighty handy. These neat threaded inserts can ...

Spark plugs that haven't been changed for a long time can become one with the cylinder head. Fortunately, it's possible to repair damaged threads instead of scrapping the head. (Photograph by Chris ...

Q I recently took my '02 Chrysler minivan in for 100,000-mile service and was told that one of the spark plugs would not come out of the cylinder head. The shop tried, but it would only come out so ...