Should There be Oil On Your Spark Plug?

spark plug, oil on your spark plugReading spark plugs used to be at art that almost every mechanic knew.  They could tell by looking at the color of the electrode and insulator how old the plug was and how the car was running.  If you’re interested in learning this dying art, check out this cool article about Champion Spark Plugs.  So should there be oil on your spark plug?  Even if you’re not a spark plug whisperer, you still probably know that oil on a spark plug indicates a problem.

There are really only 2 ways you can get oil on your spark plug:

  1. Piston Ring Blow-By
  2. Bad Spark Plug Tube Seal

First, let’s talk about bad valve seals.  A bad valve seal will allow oil to drip from the cylinder head past the valve into the combustion chamber.  If you’ve got this problem you probably see a small puff of blue smoke when you start your car every morning.  This will not leave oil on your spark plug as the leak doesn’t happen fast enough to allow a significant amount of oil into the combustion chamber while driving so the oil burns up quickly after you start your car and your spark plug will be dry.

Bad piston rings will let combustion gases into the crankcase and engine oil into the cylinder.  If the blowby gets real bad, the oil can foul your spark plug. In this case an easy, but a temporary fix is to install a spark plug anti-fouler.  This device spaces the spark plug far enough out of the combustion chamber that it won’t get covered by so much oil.  If you suspect this a compression test of your engine can help you find out which cylinder has a bad ring and how bad it is.

Bad spark plug tube seals are the most common cause of oil on your spark plug.  The reality is the oil isn’t really on your spark plug but it’s pooled up in the bottom of the tube the spark plug sits in so when you pull the plug out it gets covered in the pooled up oil.  If this is the case, you’ll have oil on the tip of the spark plug as well as the white insulator and usually on the spark plug boot as well. This is caused by a bad spark plug tube seal. Replace the tube seal requires removing the valve cover and changing the valve cover gasket as well as the spark plug tube seals.

If the hard part repair doesn’t make sense for your vehicle, consider using BlueDevil Oil Stop Leak to restore your spark plug tube seals to keep your spark plugs oil free! 

You can pick up BlueDevil Oil Stop Leak at one of your local auto parts stores like:

  • AutoZone  
  • Advance Auto Parts
  • Bennett Auto Supply
  • CarQuest Auto Parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Fast Track
  • Bumper to Bumper Auto Parts Specialists
  • S&E Quick Lube Distributor
  • DYK Automotive
  • Fisher Auto Parts stores
  • Auto Plus Auto Parts stores
  • Hovis Auto & Truck Supply stores
  • Salvo Auto Parts
  • Advantage Auto Stores
  • Genuine Auto Parts stores
  • Bond Auto Parts stores
  • Tidewater Fleet Supply
  • Bumper to Bumper Auto Parts
  • Any Part Auto Parts
  • Consumer Auto Parts

Pictures Provided By:

spark_plug. jpg – By Pawzi – LIcensed by Getty Images – Original Link

29 responses to “Should There be Oil On Your Spark Plug?

  1. Morning

    please help i notice one of my spark plugs and my car is not perfoming like it use to be. can blue devil oil stop leak help in my problem? my car is a 1.4 vw polo vivo 2013 vin no: AAVZZ6SDU029688

    1. Mandla-

      Thank you for asking about your Volkswagen Polo Vivo. The most likely cause for oil getting on the spark plugs is a leaking valve cover gasket. If that is the case, we recommend using the BlueDevil Oil Stop Leak. You should expect to start seeing improvement after approximately 100-200 miles of driving.

      Thank you!

      -BDP

    1. Rajesh-

      Thank you for asking about your Volkswagen Polo. Bad spark plug tube seals are the most common cause of oil on your spark plug.  The reality is the oil isn’t really on your spark plug but it’s pooled up in the bottom of the tube the spark plug sits in so when you pull the plug out it gets covered in the pooled up oil.  If this is the case, you’ll have oil on the tip of the spark plug as well as the white insulator and usually on the spark plug boot as well. This is caused by a bad spark plug tube seal. The BlueDevil Oil Stop Leak would be able to treat this kind of a leak. You should expect to start seeing results after approximately 100-200 miles of driving.

      Thank you!

      -BDP

  2. hello. i have a 2013 dodge avenger se 2.4l, this is a mitsubishi engine. i just changed the spark plugs and there is oil on number 2, but not at the tip of the electrode but where the plug socket wraps around the spark plug to untighten or tighten it please advise if you know what this could be. thank you very much.

    1. Roberto-

      Thank you for asking about your Dodge Avenger. Oil around the spark plugs is oftentimes due to valve cover gaskets leaking. Have you noticed any issues with engine performance? Replacing the valve cover gasket should solve the problem.

      Thank you!

      -BDP

      1. good morning. i have not experienced any performance issues. she runs as strong as can be. i will changed the valve cover gasket and go from there. thank you very much for your help.

  3. I just changed the spark plugs on a 2004 chevy aveo lt that havent been changed in what likely a decade (car was purchased in said form). Had a oil change on the car before replacing the spark plugs and noticed they were all covered in oil. Shortly after I replaced the plugs I started up the car and noticed that white smoke was coming from the exhaust and have no idea if this was caused by my changing of the plugs (new double platinum plugs) or there is some other factor at play?

    1. Xavier-

      Thank you for asking about your Chevy Aveo. The white smoke out of the exhaust would indicate water/coolant burning. Have you noticed a loss of coolant? Are you noticing any other drive ability issues? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.

      Thank you!

      -BDP

  4. I changed my valve cover gaskets an spark plugs about two months ago. Long story short I bought ignition coils an started replacing them an in a few sockets oil is in the sockets. What should I do to get the oil out spark plug holes an could the problem be the spark plugs not being tighten good enough

    1. Dante-

      Oil getting into the spark plug well is typically a symptom of leaking valve cover gaskets, if the gasket is not sealed around the spark plug well. You may want to recheck the gaskets to make sure that is the issue, as another possibility would be if the valve cover itself is broken/cracked.

      Thank you!

      -BDP

  5. HELLO!
    I HAD ALOT OF OIL ON MY IGNITION BOOT.
    I WENT AHEAD AND REMOVED SPARK PLUG WITHOUT REMOVING OIL FIRST FROM THE SPARK PLUG WELL.
    SHOULD I TRY TO REMOVE OIL NOW AFTER I HAVE REMOVED THE SPARK PLUG?
    CAN I HURT SOMETHING BY JUST INSTALLING THE SPARK PLUG AND LETTING HER RUN UNTIL THE SMOKE GOES AWAY?

    1. Harvey-

      Oil leaking into the spark plug wells is an indication of a very serious issue. Most likely, this is a result of bad piston rings or a cracked valve cover. Continuing to run the engine under this condition could cause further damage. We recommend bringing the vehicle in for the hard part repair.

      Thank you!

      -BDP

  6. Dear Sir,
    I have a petrol car . My engine oil consumption is increased drastically. Sometimes I have to top up 2 litre just in 300 kilometer run. I also got it checked at authorised service centre at Tata Motors India. They said to overhaul engine which is quite costly.
    Please suggest a n appropriate solution.

    1. B C Bhatt,

      Thanks for your question about your car’s oil consumption. To go through that much oil you would have to have a pretty big oil leak causing dripping on the ground. If that is the case the leak should be pretty easy to find and fix. If you don’t have drips on the ground then your engine is burning the oil. If the car smokes heavily when it’s started but stops within a minute or two then you probably have bad valve seals. If your car smokes all the time when you’re driving then you’ve may have bad piston rings.

      Thanks again for your question!
      -BD Auto Pro

  7. My 2006 Chrysler 300 over heated due to my thermostat being stuck closed now I have water in my oil, miss fire in piston 4 (there is oil on the plug), and have white smoke coming out of the exhaust. If I change the thermostat,oil , and my spark plug then add blue devil will it fix my problem.

    1. Chad-

      Thank you for asking about your Chrysler 300. Based on your description, it sounds like you may be getting combustion/exhaust gases pumping back into the cooling system. You can use a “Block Dye Tester” to confirm whether or not that is the case.
      BlueDevil Head Gasket Sealer will still work if your vehicle is getting combustion/exhaust gases blowing into the cooling system and creating pressure. To give yourself the best overall chance of BlueDevil working successfully, in addition to the directions, you should remove the spark plug from the cylinder with the leak; this will be the spark plug from the cylinder with the low compression reading. If you are not sure which one that is, you may pull all of the spark plugs and will notice one will have a white-crystal-like substance on it and/or may look dirty; this is the plug you should pull. Leave that plug out for the 50 minute idle in order to relieve the pressure from building up and thus allowing the product to seal properly. Be sure to follow the guidelines for the proper amount to use based on the size of your cooling system. Also, you would want to change the oil before and after the BlueDevil procedure.

      Thank you!

      -BDP

  8. Hi guys I’m also experiencing the same problem of wet spark plugs I’m driving a vw fox 1.8 my number 1 and 2 plugs they always wet when i check them,and the performance is not satisfying when the engine runs you feel a mis-fire of some sort and the dying/cutting of power,please help what might be the problem and how to fix it?

    1. Matiwane-

      Thank you for asking about your Volkswagen Fox. A majority of the time, oil getting on the spark plugs is a sign of bad o rings or leaking valve cover gasket. Have you noticed a loss of oil? Have you seen any smoke coming out from under the engine or through the exhaust pipe? Replacing the spark plugs for your 1 and 2 cylinders should correct the misfires and increase engine performance.

      Thank you!

      -BDP

  9. Hi,
    I am getting oil ONLY on the thread of the spark plug, and that too only on one of the four spark plugs. What could be the reason.

    1. Anuj-

      Faulty piston rings or a leaking valve cover gasket could cause oil to get onto the spark plugs. Unfortunately, this would be an indication of a very serious issue, so you may want to have the vehicle inspected sooner rather than later.

      Thank you!

      -BDP

  10. Please I am using Kia Rio 2006 model I found oil on the spark plugs 1, 2 and 3. What will be the solution to this problem.

    1. Takyi-

      Thank you for asking about your Kia Rio. Oil found on the spark plug could be attributed to worn valve cover gaskets, bad piston rings or leaking O-rings. It would be best to replace the spark plugs you found the oil on. It may be best to bring the vehicle to an ASE certified mechanic so they can diagnose where the loss of oil is coming from.

      Thank you!

      -BDP

  11. Hi. My Chev Sonic 1.4 turbo does not have any signs of leaking oil in the valve cover gasket. But 3 of the 4 Spark plugs were found to have oil. Upon removing the spark plugs, there is unburned visible oils on top of the pistons. There is no sign that oil is leaking into the Spark plug well from the valve cover gasket, but the plugs threats have oil. I haven’t seen the smoke, but experienced the loss of power when accelerating as well as rough idling

    1. Hlaba-

      Due to the fact that you are seeing oil, we recommend adding 1 bottle of BlueDevil Oil Stop Leak. You can expect to start seeing results after approximately 100 miles of driving.

      Thank you!

      -BDP

  12. Hi guys, I have toyota corolla 1.4i 2006.the engine misfires and shaking. I checked the sparkplug and found that number 1 has oil and is black. When this problem started I took it to the mechanic to have the gasket cover changed as we suspected the oil leak but the problem persist. In this case can blue devils top leak assist? It is very difficult to solve this problem since the engine light is not on. Please assist
    Thanks in advance

    1. Desmond-

      Please give our tech support team a call at 888-863-0426. We would like to discuss your vehicle in more detail so that we can determine whether or not BlueDevil may be able to help your vehicle.

      Thank you!

      -BDP

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