# Can driving with misfire cause engine damage? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** ford\ **Created:** [October 17, 2020, 4:46am UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290 "2020-10-17T04:46:36Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Mrnicefordguy](https://avatars.discourse-cdn.com/v4/letter/m/a88e57/32.png) [@Mrnicefordguy](https://community.cartalk.com/u/Mrnicefordguy)\ **Post date:** [October 17, 2020, 4:46am UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/1 "2020-10-17T04:46:36Z")
Title. Can driving with single cylinder misfire due to lean condition cause major engine damage and if so what? (Piston rings, valve stems, etc.) I have a misfire on cylinder 3 on my 4 cyl car for the first 1-2 minutes of driving then it goes away. What damage do I risk to my engine if any if I continue to drive it like this? Mechanic said car probably has a weak fuel pump. My funds may not allow me to fix the issue for another couple weeks ---
**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:** [October 17, 2020, 10:13am UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/2 "2020-10-17T10:13:24Z")
A mis fire puts unburned fuel in the exhaust and can overheat and damage the catalytic converter. Try another mechanic, I doubt a weak fuel pump would cause a misfire consistently on the same cylinder. BTW is this a 1968 Cortina with 145,000 miles? How about telling us what the car is, make, model, year, mileage, maintenance history etc. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [October 17, 2020, 12:54pm UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/3 "2020-10-17T12:54:31Z")
> [@SteveCBT](#): > > A mis fire puts unburned fuel in the exhaust What if the misfire is because an injector isn’t injecting fuel? ---
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [October 17, 2020, 3:31pm UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/4 "2020-10-17T15:31:24Z")
It’s not perfect, but most manuals tell you to shut off the engine if the CEL is blinking, to avoid doing damage; but driving with the light on is OK. You might have leaking injector. Pour a bottle of Techron cleaner into your gas and give it some time and miles to maybe clear up the problem. ---
**Author:** ![davepsinbox\_157004](https://avatars.discourse-cdn.com/v4/letter/d/73ab20/32.png) [@davepsinbox\_157004](https://community.cartalk.com/u/davepsinbox_157004)\ **Post date:** [October 17, 2020, 8:29pm UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/5 "2020-10-17T20:29:45Z")
> [@It\_s\_Me](#): > > What if the misfire is because an injector isn’t injecting fuel? Is that what the “lean condition” means? I’d think too little fuel wouldn’t necessarily mean none. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [October 18, 2020, 2:48am UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/6 "2020-10-18T02:48:21Z")
It might. Cat at risk. Also could overheat and damage valve etc. Could be benign for the most part too. Best to get it diagnosed asap imo. ---
**Author:** ![Dappersworth](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/dappersworth/32/22638_2.png) [@Dappersworth](https://community.cartalk.com/u/Dappersworth)\ **Post date:** [October 18, 2020, 2:58pm UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/7 "2020-10-18T14:58:21Z")
A bad fuel pump would cause a misfire on all cylinders randomly, not just one cylinder. Likely causes: Intake manifold gasket Fuel injector Fuel injector wire (personal experience with this one) How do you know it’s a misfire due to a lean condition? ---
**Author:** ![natepuisis\_160295](https://avatars.discourse-cdn.com/v4/letter/n/7ab992/32.png) [@natepuisis\_160295](https://community.cartalk.com/u/natepuisis_160295)\ **Post date:** [October 18, 2020, 7:44pm UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/8 "2020-10-18T19:44:25Z")
“Lean” means that there is either too much air or not enough fuel. Instead of replacing parts, this can likely be diagnosed quickly by checking fuel trim values on a scan tool with live data. You may also have more than one issue, like a bad spark plug and a vacuum leak for example. ---
**Author:** ![davepsinbox\_157004](https://avatars.discourse-cdn.com/v4/letter/d/73ab20/32.png) [@davepsinbox\_157004](https://community.cartalk.com/u/davepsinbox_157004)\ **Post date:** [October 18, 2020, 8:25pm UTC](https://community.cartalk.com/t/can-driving-with-misfire-cause-engine-damage/171290/9 "2020-10-18T20:25:05Z")
Again, “lean” doesn’t necessarily mean _no_ fuel. It means an improper mixture. I agree with @Dappersworth that it’s not the fuel pump. Bad or leaking injector is more likely.