If you notice oil leaking into the spark plug well, it usually means a worn or damaged valve cover gasket or spark plug tube seal. Oil in the spark plug wells can cause misfires, poor performance, and increased fuel consumption. If left untreated, it may damage ignition coils and spark plugs, leading to more costly repairs.

What does it mean if oil is leaking into the spark plug well?

This condition indicates that oil is seeping past worn seals or gaskets and collecting around the spark plugs. It prevents proper spark delivery and may cause the engine to run rough or misfire.

Common causes of oil in the spark plug wells

• Worn or cracked valve cover gasket
• Damaged spark plug tube seals
• Loose or warped valve cover
• Excess crankcase pressure pushing oil past seals

Why do you need to fix this problem quickly?

Oil in the spark plug wells can cause misfires, damage to ignition coils, and increased emissions. Prolonged leaks may also lead to low oil levels and poor lubrication, risking engine damage.

How do you know when to get it checked?

You should book an inspection if:

• Your car misfires, runs rough, or loses power
• You see oil when removing ignition coils or spark plugs
• The Check Engine Light is illuminated
• You notice oil leaks around the top of the engine
• You smell burning oil from the engine bay

What happens during an assessment?

A mechanic will:

1. Inspect the valve cover gasket and spark plug tube seals
2. Check ignition coils and spark plugs for oil contamination
3. Replace the valve cover gasket and seals if required
4. Clean and dry the spark plug wells
5. Replace damaged spark plugs or coils if necessary
6. Test the engine to confirm smooth operation

How much does it cost to fix?

Replacing the valve cover gasket and seals typically costs $250–$600. If spark plugs and ignition coils are damaged, total costs may rise to $500–$1,200+ depending on the vehicle.

Is it unsafe to drive with oil leaking into spark plug wells?

Yes. Oil contamination can cause severe misfires, reduced performance, and even stalling, which makes driving unsafe. The issue should be repaired immediately to prevent further engine and ignition damage.