Q: Plugs get oil on them and misfire

asked by on

The plugs in my car keep misfiring. For some reason, the plugs under the coil are getting oil on them. I was wondering what can cause this. My car has a North Star, 4.6-liter engine. Do you have any idea what the underlying issue is? Thanks.

The top most part of your engine is called the valve cover. On a V-shaped engine, you should have 2 valve covers. These valve covers are bolted to the top of the cylinder head and have gaskets in between the two mating surfaces to keep oil from leaking out.

In the center of your valve covers should be 4 holes in each one. These holes represent where the spark plugs are inserted into their sleeves. The valve cover gasket set comes with what are called spark plug tube seals which go around the sleeves to prevent oil from getting onto the spark plugs. These tube seals can go bad just like the valve cover gaskets can and will occasionally require replacement. Unfortunately, even if the valve cover gaskets are not leaking and the tube seals are, the valve cover gaskets will still have to be replaced as the valve covers will need to be removed to access the tube seals. I would recommend having this job performed by a certified technician for best results.

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. Plugs get oil on them and misfire

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: Car has a random misfire/jerking/hesitation only between 1200 and 1500 rpms, when it does misfire it does it 1 - 4 times

The dealer could well be correct on this - coils do go bad gradually sometimes, and "random misfire" is the common symptom. If the valve cover is leaking oil into the spark plug recess in the cylinder head, this can...

Q: When raining, brakes grind first few stops and then clear up

The brake pads have metal in them, and the rotors are made of metal, and when it rains they get wet and surface rust will immediately start to rust the rotors. As soon as you start to drive off, the...

Q: Egr and evap codes 455 & 405

The trouble code P0405 is for the EGR sensor. This code indicates that the sensor is not giving correct voltage readings. You'll need to replace the sensor and the sensor hoses. The hoses can clog or burn through which causes...

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...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...