* Valve Cover Gasket Leak: This is the most common cause. The valve cover gasket seals the top of the engine, and if it's worn or damaged, oil can leak down and onto the spark plugs. This is often a relatively straightforward repair.
* Worn Piston Rings: If the piston rings are worn, they won't seal the combustion chamber properly. This allows oil to be pushed past the rings into the combustion chamber, which can then be burned or deposited on the spark plugs. This is a more serious problem requiring engine work.
* Cracked Cylinder Head: A crack in the cylinder head can also allow oil to leak into the combustion chamber, leading to oil on the spark plugs. This is a major repair.
* PCV Valve Issues: A clogged or faulty Positive Crankcase Ventilation (PCV) valve can cause excessive crankcase pressure, forcing oil past seals and onto the spark plugs.
* Oil Filter Issues: Although less common, a poorly installed or failing oil filter could lead to increased pressure and oil leaks.
Which is it? It's impossible to say definitively without inspecting the engine. The amount of oil, the location of the oil (just on one plug, or multiple?), and other symptoms (like blue smoke from the exhaust, loss of engine power, or low oil level) can help narrow down the possibilities.
Recommendation: You should have a qualified mechanic inspect your Sebring's engine. Ignoring oil on the spark plugs can lead to further engine damage, misfires, and ultimately engine failure. A timely diagnosis and repair will save you money and keep your car running smoothly.
