# Spark plug has a black deposit **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [September 12, 2007, 11:59pm UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529 "2007-09-12T23:59:22Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![b11b11](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@b11b11](https://community.cartalk.com/u/b11b11)\ **Post date:** [September 12, 2007, 11:59pm UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529/1 "2007-09-12T23:59:22Z")
What is the name of the solution that “loosens” the black deposit on a spark plug? ---
**Author:** ![DARTMAN69](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/dartman69/32/29_2.png) [@DARTMAN69](https://community.cartalk.com/u/DARTMAN69)\ **Post date:** [September 13, 2007, 12:04am UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529/2 "2007-09-13T00:04:48Z")
I like to call it a new spark plug. Seriously I wouldn’t waste my time trying to clean them. ~Michael ---
**Author:** ![Docnick](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@Docnick](https://community.cartalk.com/u/Docnick)\ **Post date:** [September 13, 2007, 12:10am UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529/3 "2007-09-13T00:10:35Z")
I agree that new spark plugs are the answer. However to avoid this in the future, make sure your car is not running rich, ie too much gas. This occurs in old cars when the choke stays shut. In newer cars it is the can be due to spark plug misfiring or other causes. The stuff to put in the tank used to be called “Karbout”. It can still be bought, but may be modified for newer engines so as not to interfere with the computer sensors. ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [September 13, 2007, 12:17am UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529/4 "2007-09-13T00:17:27Z")
Sooty black may mean a misfire or rich running problem. If this black deposit is somewhat hard and caked this may be oil and the cure for that is usually engine work. As mentioned, replace them rather than clean them. In the old days one could get away with cleaning plugs but with what I assume is a later model vehicle, misfires are much more noticeable and a cleaned plug may not prevent this. ---
**Author:** ![Roadrunner](https://avatars.discourse-cdn.com/v4/letter/r/d2c977/32.png) [@Roadrunner](https://community.cartalk.com/u/Roadrunner)\ **Post date:** [September 13, 2007, 1:02am UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529/5 "2007-09-13T01:02:55Z")
Wouldn’t it be prudent to locate the source/cause of the sooty plug first? Perhaps a bad plug wire? ---
**Author:** ![b11b11](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@b11b11](https://community.cartalk.com/u/b11b11)\ **Post date:** [September 13, 2007, 9:37pm UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529/6 "2007-09-13T21:37:38Z")
Engine ran for awhile while the oil level was low. I tryed soaking the plug in gas but that did not help remove the black deposit. ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [September 14, 2007, 1:28am UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529/7 "2007-09-14T01:28:35Z")
Yes, a bad plug wire can cause a plug to soot up. OP, you’re going about this all wrong. Soaking a spark plug in gas is no way to clean one, even if it were worth the time. The only proper way to clean a spark plug, and no one does this anymore, is to use a small air operated plug cleaning device that uses grit to clean them. Lacking that device, as most do, the only other method is a wire wheel and carb cleaner. ---
**Author:** ![BustedKnuckles](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bustedknuckles/32/25_2.png) [@BustedKnuckles](https://community.cartalk.com/u/BustedKnuckles)\ **Post date:** [September 14, 2007, 1:58am UTC](https://community.cartalk.com/t/spark-plug-has-a-black-deposit/4529/8 "2007-09-14T01:58:47Z")
Just replace it. You probably need a tune-up anyway.