# Spark plug carbon tracking **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [March 24, 2021, 7:40pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815 "2021-03-24T19:40:34Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [March 24, 2021, 7:40pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/1 "2021-03-24T19:40:34Z")
Here’s a picture, a little blurry, of a spark plug showing carbon tracking on the outside of the porcelain insulator. The plug is fairly new. ![IMG_20391](https://global.discourse-cdn.com/cartalk/original/3X/1/b/1b30e9a9fd64ca14a48e9f918c789a67fe529c38.jpeg) Would anyone like to guess what caused it? ---
**Author:** ![Renegade](https://avatars.discourse-cdn.com/v4/letter/r/b4bc9f/32.png) [@Renegade](https://community.cartalk.com/u/Renegade)\ **Post date:** [March 24, 2021, 7:43pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/2 "2021-03-24T19:43:17Z")
I would say cheap or bad plug wires. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [March 24, 2021, 7:44pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/3 "2021-03-24T19:44:13Z")
That occurs when the spark runs down the side of spark plug instead of to the gap. Change the plug wires or coil boots. Tester ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [March 24, 2021, 7:45pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/4 "2021-03-24T19:45:28Z")
The carbon track was existing in the old wire when the plug was installed. ---
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [March 24, 2021, 7:50pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/5 "2021-03-24T19:50:05Z")
> [@Renegade](#): > > I would say cheap or bad plug wires Autolite is not my favorite but it was not a plug or wire defect. > [@Tester](#): > > Change the plug wires or coil boots Plugs and wires are brand new. > [@Nevada\_545](#): > > The carbon track was existing in the old wire New wires were installed with the new plugs. ---
**Author:** ![NYBo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nybo/32/17281_2.png) [@NYBo](https://community.cartalk.com/u/NYBo)\ **Post date:** [March 24, 2021, 7:51pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/6 "2021-03-24T19:51:28Z")
Water in the spark plug well? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [March 24, 2021, 7:52pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/7 "2021-03-24T19:52:38Z")
> [@asemaster](#): > > Plugs and wires are brand new. > [@asemaster](#): > > The plug is fairly new. I don’t see any mention about replacing wires. Tester ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [March 24, 2021, 7:53pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/8 "2021-03-24T19:53:46Z")
Crack in the porcelain? ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [March 24, 2021, 8:13pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/9 "2021-03-24T20:13:04Z")
Contamination, your technicians will need to wear hair nets. ---
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [March 24, 2021, 8:20pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/10 "2021-03-24T20:20:46Z")
OK, it was a trick question. I cleaned the spark plug before taking the picture. Guy’s car was running rough and the check engine light was on. He went to Autozone for a code read and found a misfire, told him most common cause was plugs and wires. The clerk sold him spark plugs, a wire set, and a small tube of anti-seize. Guy goes home, installs the new plugs, packs the wire boots full of anti-seize, installs the wires, then wonders why the car runs worse than before. ---
**Author:** ![ralfherman86\_172676](https://avatars.discourse-cdn.com/v4/letter/r/977dab/32.png) [@ralfherman86\_172676](https://community.cartalk.com/u/ralfherman86_172676)\ **Post date:** [March 24, 2021, 11:25pm UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/11 "2021-03-24T23:25:52Z")
try cleaning them with break spray and then see if it happens again ---
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [March 25, 2021, 12:45am UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/12 "2021-03-25T00:45:29Z")
> [@Nevada\_545](#): > > Contamination, your technicians will need to wear hair nets. Well, maybe the one that wears a man-bun, but the bald guy surely gets a pass. 😀 ---
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [March 25, 2021, 12:47am UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/13 "2021-03-25T00:47:12Z")
> [@ralfherman86\_172676](#): > > cleaning them with break spray and then see if it happens again Nope, not cleaning anything. I work at a shop and we warranty our work for 3/36. It was new plugs and new wires or take the car and fix it yourself. ---
**Author:** ![SteveCBT](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/stevecbt/32/3192_2.png) [@SteveCBT](https://community.cartalk.com/u/SteveCBT)\ **Post date:** [March 25, 2021, 12:58am UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/14 "2021-03-25T00:58:17Z")
Agree with @asemaster , new parts if you provide a warranty. For DIY I would clean it but only if the plugs were easy to get to. Some plugs require major work to access and I would use new parts then. Besides it might now work after break spray, might be broke then 😉 ---
**Author:** ![mdixter](https://avatars.discourse-cdn.com/v4/letter/m/e36b37/32.png) [@mdixter](https://community.cartalk.com/u/mdixter)\ **Post date:** [March 31, 2021, 11:26am UTC](https://community.cartalk.com/t/spark-plug-carbon-tracking/175815/15 "2021-03-31T11:26:30Z")
This is what some people don’t get when they complain about shop prices and practices. You can try shortcuts DIY, but any decent shop that stands by its work has to fix it right.