Q: The vehicle is jerking and not firing and the plug number 4 is soaked with oil.

asked by on

I started my car last weekend and drove it. After, about 5 minutes, it started jerking very badly and it wasn't firing. There was no fault indication on the screen. I have run a diagnostic test and it didn't reveal anything. My mechanic checked the plugs and discovered that the plug number 4 is soaked in oil. The vehicle is still jerking and that plug is still oil soaked. Even when we replaced the plug, it still had the same problem.

My car has 19000 miles.
My car has an automatic transmission.

Hi there. When a spark plug has excessive oil on the plug, then there is excessive oil getting into the cylinder. This will foul out the spark plug and cause a misfire. The misfire is causing the engine to be jerky. There are three areas that cause excessive oil in the cylinder.

  • The oil scraper rings on the piston is worn and causing the oil to not crape down off the cylinder wall.
  • The Positive Crankcase Ventilation Valve (PCV) is plugged up causing the crankcase to over pressurize forcing the oil into the cylinder.
  • The valve guide seal on the intake valve is split or damaged causing oil to puddle up on the intake valve and being sucked in on the intake stroke.

Check the above areas and one of them will be the cause and repair to your symptom. If you need further assistance with your engine having excessive oil on the spark plugs, then seek out a professional, such as one from Your Mechanic, to help you.

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. The vehicle is jerking and not firing and the plug number 4 is soaked with oil.

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: Check Engine Light on - P2187 and P0420 codes

Hello. If I understand correctly, when you say "catless downpipe," you mean that you have installed a pipe without a catalytic converter. If that is the case, you are always going to have the code for catalyst efficiency. The...

Q: increased engine over load message.

Hi there. The message is coming on for the catalytic converter overheating. A misfire or leaking injector will cause the catalytic converter to overheat as raw fuel enters the exhaust system. Check the engine for a misfire and see which...

Q: I have a oil leak and now my car is shaking and cutting off.

Your oil leak may be unrelated to the vibrating or shaking, but suggests you may have a failing gasket somewhere. Gaskets can fail over time due to excessive heat and will eventually shrink causing them to fail and leak. I...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...
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...