Q: Car's #8 cylinder is misfiring

asked by on

There is a misfire in my car’s #8 cylinder. Even after changing the spark plugs and the ignition coil, I still have the misfire. When checking the compression in the cylinder, I found that it is good. Also, I checked to ensure that there is 12v going to the injector - that is fine, too. There is a code for the catalytic converter. Could the catalytic converter be causing the misfiring and if not, what do I look for next?

It is possible that your oil ring could be faulty in the number eight cylinder. If the oil ring is faulty, this can allow oil to get past the piston into the combustion chamber and therefore causing it to get burned by the spark plug. This can cause a misfire because oil is much harder to burn than gasoline.

Extended burning of oil by a spark plug can eventually foul out the spark plug. If the oil ring is the only piston ring that is bad, this can still cause the compression readings to be within specification. I would recommend having your number eight cylinder checked by a professional to determine if there is evidence of oil in the combustion chamber. If there is evidence of oil, I would recommend having the oil ring replaced.

Have the vehicle inspected by a qualified mechanic, they will be able to diagnose the misfire firsthand and make the appropriate repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Car's #8 cylinder is misfiring

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: I have a 2006 dodge caravan and I been smelling gas for about a month but it's not burning alot of gas do you have any idea what i

It is possible that you have a leak in your exhaust system. Many times you will be able to smell gas when the exhaust system has a hole in it. The most common cause of this would be the exhaust...

Q: Engine control modules replaced on a newer car

Hi there. These modules are common failures on the Jaguar XF. I am sure that this does not make you feel any better about it, but from my experience, once the modules are replaced you usually do not have any...

Q: What if I dont have power to the acc relay how do I fix it do

Hi there. It really depends as to what is causing the accessory relay to not receive power as to what is the best solution. If the relay is not properly grounded, the repair is to resolve the ground issue. If...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.