Oil in cylinder one?

2003 NISSAN SENTRA
151,000 MILES • 2.5L • 4 CYL • 2WD • MANUAL
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JACOB MARINO
  • MEMBER
  • 45 POSTS
My engine started with a low RPMs at idle (around 500), so i did i routine check on coolant, oil, and other important parts of car and noticed I was down about 3 quarts of oil. So immediately i looked for leaks but found none which means my engine is burning it. i took out the spark plugs and found black oil deposits on the cylinder 1 plug so i looked in the spark plug hole and saw a puddle of oil on the top of the piston. I don't know how to determine if it is bad rings or bad valve seals... Any tips?
Feb 5, 2023 at 6:03 PM
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STRAILER
  • ✓ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
It sounds like the oil control ring on the piston is broken but it may be the valve seals as well. But if the PCV is stuck open it can draw oil into the cylinder so we should try that first. Here is the location of the valve so you can change it out. Check out the images (below). Please let us know what happens.
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Feb 6, 2023 at 10:52 AM
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