How do I know if the PCV grommet is bad?
Documented on the 2012 Ford Mustang GT build
Published April 27, 2026
Look for oil seepage around the grommet, cracked or flattened rubber, and listen/observe for idle changes when applying a spray test around the area.
Full Answer
Look for oil seepage around the grommet, cracked or flattened rubber, and listen/observe for idle changes when applying a spray test around the area. Physical inspection and replacement are common for confirmation.
Documented In This Build
Related Knowledge
What usually causes a rough idle on a 2012 Mustang GT?Can I just clean the throttle body to fix the idle?What torque should I use for the coil mounting bolt?What causes oil to fill the spark plug wells?Can I drive the car if the plugs are covered in oil?How often should I clean the fuel injectors?Can I use a pour-in fuel additive instead of an inline cleaning kit?Can I reuse the old springs with new strut cartridges?
Related Parts
Throttle body gasket / O-ring
Motorcraft / aftermarket$12
PCV valve / valve cover grommet
Motorcraft / aftermarket$25
Vacuum hose (assorted)
generic$10
Brake cleaner / contact cleaner (for quick spray checks)
generic$5
Throttle body cleaner
CRC (typical)$8
Related Tools
Ratchet and metric socket setGeneric
Screwdrivers (flat & Phillips)Generic
Hand vacuum pump / smoke machine (optional)Generic
Shop rags and gloves
Torque wrenchGeneric
OBD-II scanner / code readerGeneric / Bluetooth adapters commonly used
