Skip the auto shop - Our mechanics make house calls

Q: Misfire on cylinder 8

asked by on

According to the code check, I have a misfire on cylinder 8. The car seems to run fine, except occasionally when I'm sitting at idle. When I'm idling, it sometimes stumbles or shudders, but it rarely dies. I had the spark plugs changed before. Could a bad spark plug cause this, or might there be something else going on?

A: It could be the spark plug, ignition coil, ...

It could be the spark plug, ignition coil, or coil boot causing the misfire. You may also have dirty fuel injectors that need to be cleaned. Have the ECM scanned to see if the misfire code is P0308. This code refers to cylinder #8. If so, check the spark plug, coil, and boot for issues and replace them if you find any. Otherwise swap the #8 and #7 coil and boot. If the misfire happens again and moves to cylinder #7, then you know to replace that coil and boot to fix the issue. If you need assistance, a certified mobile mechanic from YourMechanic can inspect the cause of the misfire at your home or office.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Headlights going in and out.

Looking at the wiring diagrams for your vehicle, I see that both the radio and courtesy lamps (interior lights) share a common ground. It could be this ground it is not making good contact and gets disturbed when going over...

Q: Vehicles Check Engine light blinks and then stays on, runs rough like on 6 cylinders/misfiring when wet.

Hi there. Check the spark plugs and see if they are sparking. Get a code reader and check for any codes that could be stored in the computer as the check engine light is on. The code will give you...

Q: My key fob will not open my car doors or trunk. I inserted a new battery in the fob and that did not help. What cld be the proble

Based on your description, I believe that the first issue is the lack of programming for your new key fob. If the dealership told you that the key requires programming and that was not done, this is the reason that...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...