Skip the auto shop - Our mechanics make house calls

Q: Misfire

asked by on

what would make a number 2 spark plug have a miss fire..??
My car has an automatic transmission.

A: The valve cover should be checked first to ...

The valve cover should be checked first to see if it is leaking oil into the spark plug tubes in the head. The leaking oil that's getting onto the spark plug wire and plug can cause it to arch to the ground cause the spark to not reach the spark plug.

You should remove the ignition coil over the spark plugs and check to see if oil is on the boots, this would indicate that the valve cover is leaking. Once this is checked, replace valve cover and spark plug tube seals as necessary. Afterwards, clean out the spark plug holes and replace spark plugs and spark plug wire boots. This is the most common problem you will find with the misfire of one or more cylinders.

If you need assistance with this, consider YourMechanic, as one of our mobile technicians can come to your home or office to diagnose the misfire firsthand and make the necessary repairs to your car.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Truck is running rough engine light. Keep call code

The catalyst may give off a rotten egg smell if you are running rich from an engine misfire. You will need to have the two cylinders that are misfiring diagnosed to see if they have low compression or the valves...

Q: Sometimes my car won't start

Hello, this happens a lot on this vehicle. This is a problem with the security system. The issue is not actually the security system but the computer CAN communication lines. These lines can have a poor connection causing the computer...

Q: My car was smashed just an hour ago

Hello. First of all, I hope that everyone is okay after this accident. The first thing to do would be to make sure that the accident was correctly reported. This job will be one for a body shop. Have the...

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...