Symptoms
- Burning oil smell traced to the top of the engine near the spark plugs/ignition coils
- Rough idle, misfires, or a check engine light for a misfire code
- Oil visible when removing an ignition coil or spark plug
- Smell may worsen after the engine has been running for a while
Likely causes
- CommonLeaking valve cover gasket allowing oil to reach the spark plug wellsOil seeping past a worn valve cover gasket can pool in the recessed spark plug tube areas on many engines, eventually contacting the plugs and coils.
- CommonWorn spark plug tube seals (separate from the main valve cover gasket)Many engines have individual small seals around each spark plug tube that wear independently of the main gasket.
- PossibleOil dripping down from a higher leak point above the ignition componentsA leak elsewhere on the upper engine can drip down and pool in the same area even if the valve cover gasket itself is fine.
What to do
- Have a mechanic or carefully (if experienced) remove an ignition coil or spark plug boot to visually check for oil pooling in that well.
- Have any misfire-related check engine codes read with a scan tool, since oil-fouled plugs commonly trigger these.
- Clean any oil found in the spark plug wells before replacing seals, since leftover oil will continue to cause problems even with a new gasket.
- Replace the valve cover gasket and/or individual spark plug tube seals as needed, since both commonly wear together on many engines.
- Replace any spark plugs or ignition coils that were fouled by oil, since they often can't be reliably cleaned and reused.
Tools and parts
- Basic socket set
Valve cover gasket with spark plug tube seals for your engineSearch: “valve cover gasket with spark plug seals”
Spark plugs for your vehicleSearch: “spark plugs”
When to call a pro
See a mechanic if you're not comfortable removing ignition coils/spark plugs yourself, or if misfire codes are present, since oil-fouled plugs and coils sometimes need replacement alongside the gasket repair.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.