PriceProtect™
DriveShield™
GarageGuard™
Services
Insurance
Car Insurance
Compare Car Insurance with Jerry
Jerry’s Expert Advice
Car Insurance Estimates
Home & Renters Insurance
Renters Insurance
Loans
Car Loan
Compare Car Loans with Jerry
Jerry's Expert Advice
Car Loan Guides
Repairs
Car Repair Estimates
Repair Estimates for Popular Services
Advice
Read Car Content
Browse Jerry Car Advice
Check Out Expert Car QnA
Learn About How We Create Content
Jerry Data & Research
What does oil on a spark plug mean?
My engine keeps misfiring, so I decided to take a look for myself. It seems like there’s some oil on my spark plugs, but I’m not sure where it could be coming from. What does oil on a spark plug mean, in terms of car problems?
Kathryn Mae Kurlychek · Updated on
Reviewed by Shannon Martin, Licensed Insurance Agent.
If you notice oil on your spark plugs, it could mean there’s a leaky valve or gasket somewhere under your hood. Over time, excessive heat and natural wear and tear to gasket heads or valve covers can cause leaks that spew directly into your spark plug holes.
In other cases, the damage may wind up being more severe. Here are a few other common reasons you may find oil on a spark plug, and what it means:
- Faulty Crankcase Ventilation. Clogs in the crankcase breather can cause oil to leak into your combustion chamber. You’ll know this is your problem if you’re also experiencing a decrease in your engine’s performance, such as slower acceleration.
- Faulty Intake Valve Seals. Valve seals help ensure your car’s fuel doesn’t mix with other liquids in your vehicle’s system (like oil). If the seals have worn out, the oil may leak through, damaging your spark plugs. Valve seal replacements can be an expensive repair.
- Faulty Pistons or Piston Rings. If your problem is with the engine’s piston or piston rings, you may be facing a hefty mechanic bill. Symptoms may include dark exhaust smoke and decreased engine performance.
No matter the issue, if you find oil on your spark plugs it’s a good idea to replace them to avoid further damage to your vehicle.
Finding out what’s wrong with your car can be stressful—but finding the best
car insurance
doesn’t have to be. With Jerry
, you can access competitive quotes from dozens of leading insurance providers in under a minute. A
licensed insurance broker
that offers end-to-end support, the Jerry app gathers affordable quotes, helps you switch plans, and can even cancel your old insurance policy. On average, Jerry users save $800+ a year on car insurance!View full answer
- Gregory R.
WHY YOU CAN TRUST JERRY
Jerry partners with more than 50 insurance companies, but our content is independently researched, written, and fact-checked by our team of editors and agents. We aren’t paid for reviews or other content.
Join 4M+ members in lowering their car insurance
You Might Also Be Interested
Read Advice From Car Experts At Jerry
What Others Are Asking
Browse More Content
Insurance in Your State
Easiest way to compare and buy car insurance
No long forms
No spam or unwanted phone calls
Quotes from top insurance companies
