The Essential Guide to Troubleshooting Oil on Spark Plugs

The spark plug being wet with oil could be from three things. 1. worn rings. 2. hardened valve guide seals. 3. stuck rings on that cylinder ( ... The valve cover has a seal that goes around each spark plug tube. If that seal leaks you will get a slight amount of oil on top of the spark ... Spark plug tubes harden where they meet the valve cover. This will allow oil to pass over time. You might be able to reuse the valve cover but ... If there is oil in the bottom of the well chances are the valve cover gasket is leaking. There is a seal around the bottom of each well. Cleaning the spark plug with carb cleaner should be fine. Inspect the plug for damage on the electrodes. If no pitting or excessively large gap, ... If you have oil on the spark plugs then you most likely have faulty piston rings or valve stem seals. You'll need to do a compression test. If ... If you have oil in only one of the cylinders, most likely either the valve cover gasket is leaking or the head gasket is leaking. If the tip of the coil is wet with oil you have plenty in the well. If not, take a twisted paper towel and work it down along the side of the ... If oil persists in the spark plug threads or plug wells over an extended period, it becomes a significant problem. This can lead to several issues. The fix is to replace the valve cover and the 6th gen covers don't have the oil leak issue while being a direct fit replacement.