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Porsche // Cayman 718C (982C) 2017>> // Cayman GT4 Clubsport
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- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
The valve stem seal, OEM part number 993 104 111 02 (sometimes superseding 993 104 111 01), is a component for the Porsche 993 series.
These seals are installed around the valve stems and serve to regulate, not entirely block, oil flow into the combustion chamber. They wipe excess oil off the valve stems and prevent undue oil burning or plug fouling. They are applicable across various 993 configurations—including the naturally aspirated Carrera and the Turbo variants—for 1994–1998 models.
Fits:- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
Why You Should Replace Them
Over time, valve stem seals, typically rubber or elastomeric, can harden, crack, or shrink, especially under high heat and engine age—which compromises their sealing effectiveness.
Visible Symptoms:
- Blue exhaust smoke, particularly upon a cold start—leftover oil seeps past hardened seals and burns in the combustion chamber.
- Increased oil consumption without noticeable external leaks, as oil is being burned rather than escaping visibly.
- Smoke or puffing at idle or after deceleration, when high vacuum draws oil past failing seals.
- Compression or misfiring issues—oil-fouled spark plugs can disrupt ignition, and carbon buildup may mimic compression loss.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310411102
The product you are viewing cross references to these numbers