What could cause the spark plug to arc off the socket and exhaust manifold when removing the spark plug? Obviously the ignition was in the off position.

This same plug tends to get carbon deposits over time. I now suspect I may need more grounds.. But the spark plug arcing is weird.

It's a 1993 c1500/Silverado, 4.3l TBI.

  • As soon as the socket gets close to the plug it arcs? And then arcs again as you’re removing the plug from the well? – Ben May 31 '18 at 19:46
  • I only noticed it twice, then disconnected the battery terminal. But it arced with the socket loosely on, which touched the manifold. – Derelict May 31 '18 at 20:10
  • 1
    You may have a relay that isn't disengaging... either that or something is something charge... what diagnostics have you done if any? – kyle_engineer May 31 '18 at 23:10
  • No diagnostics yet, I just noticed last night. I do have power going from the battery to the amp (w/ an inline fuse) - just throwing that out. But it has been wired this way for years.. – Derelict May 31 '18 at 23:13
  • 1
    Inductive kickback from the coil discharging through the plug? – Old_Fossil Jun 1 '18 at 8:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.