# What might cause a misfire? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** neon, dodge\ **Created:** [March 23, 2011, 5:44pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914 "2011-03-23T17:44:39Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![indy4192](https://avatars.discourse-cdn.com/v4/letter/i/aeb1de/32.png) [@indy4192](https://community.cartalk.com/u/indy4192)\ **Post date:** [March 23, 2011, 5:44pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/1 "2011-03-23T17:44:39Z")
My dad’s 97 dodge neon is showing a misfire in the number 4 cylinder. He replaced the spark plug but still getting that code and engine not running smooth. What other things could cause this? Engine has about 130,000 miles on it, had been running fine. ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [March 23, 2011, 5:55pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/2 "2011-03-23T17:55:02Z")
bad plug wire, bad distributor, bad ignitor, bad distributor cap that gets wet or is close to a ground path, new spark plug that is bad or improperly gapped, are just a few of the possibilities. ---
**Author:** ![indy4192](https://avatars.discourse-cdn.com/v4/letter/i/aeb1de/32.png) [@indy4192](https://community.cartalk.com/u/indy4192)\ **Post date:** [March 23, 2011, 6:02pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/3 "2011-03-23T18:02:38Z")
he is trying to find out what it is, what if any damage is happening to the engine while he is driving it in this condition? ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [March 23, 2011, 6:04pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/4 "2011-03-23T18:04:32Z")
Misfires can be expensive if you keep driving it. He should park it until the problem is discovered and fixed. ---
**Author:** ![indy4192](https://avatars.discourse-cdn.com/v4/letter/i/aeb1de/32.png) [@indy4192](https://community.cartalk.com/u/indy4192)\ **Post date:** [March 23, 2011, 6:10pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/5 "2011-03-23T18:10:47Z")
due to it being the only car, it is the only means of transportation for my sister to get to and from work. ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [March 23, 2011, 6:17pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/6 "2011-03-23T18:17:28Z")
Replace the plug wires, distributor cap and rotor and see if that cures it… ---
**Author:** ![mark9207](https://avatars.discourse-cdn.com/v4/letter/m/71c47a/32.png) [@mark9207](https://community.cartalk.com/u/mark9207)\ **Post date:** [March 23, 2011, 7:17pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/7 "2011-03-23T19:17:05Z")
He replaced the spark plug? Just one? Why not all four? What about the wires? On this car, common causes of a misfire include carbon tracking on the coil pack or spark plug wires, spark plug tube seal leaks (oil will accumulate in the tube, deteriorating the wire boot and cause arcing. Tube seals are included with a valve cover gasket kit), worn or damaged spark plug, and the list goes on. From there, it’s electronic or fuel problems that can cause a misfire, and last, mechanical issues. Ignition issues are the easiest to troubleshoot, so start there. And yes, driving the car in this condition can and will cause damage, some kinds of damage quite severe and expensive, like melting down the catalytic converter. ---
**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\ **Post date:** [March 23, 2011, 7:56pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/8 "2011-03-23T19:56:49Z")
Finish troubleshooting the ignition since, as noted, it is the easiest stuff to worry about. If that doesn’t help check the compression. Misfire doesn’t literally mean a lack of spark. It means a lack of combustion. Combustion requires air + fuel, compressed, and then ignited by spark. So outside of spark issues you have compression, fuel, and air. ---
**Author:** ![indy4192](https://avatars.discourse-cdn.com/v4/letter/i/aeb1de/32.png) [@indy4192](https://community.cartalk.com/u/indy4192)\ **Post date:** [March 23, 2011, 9:10pm UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/9 "2011-03-23T21:10:30Z")
No he replaced all 4 and it still is saying misfire in number 4. ---
**Author:** ![motorking](https://avatars.discourse-cdn.com/v4/letter/m/94ad74/32.png) [@motorking](https://community.cartalk.com/u/motorking)\ **Post date:** [March 26, 2011, 11:10am UTC](https://community.cartalk.com/t/what-might-cause-a-misfire/62914/10 "2011-03-26T11:10:57Z")
Make sure you are getting spark? Next check compression. You can find a great video on misfire diagnosis at [autolite.com](http://autolite.com). Click on the learn more tab at the top and then open the autolite challenge video on misfire diagnosis