Exhaust Valve. Porsche 997.2 Turbo / 991 Turbo 3.8L 2010-16 › 9A110532600

Exhaust Valve.

Fits

• Porsche 997.2 3.8L 2010–13 Engine code MA1.70 
• Porsche 991.1 3.8L 2014–16 Engine code MA1.71
  
  Diagram ref no 1
  
  Check fitment for your specific vehicle (model, year, engine) before ordering.
  
  What This Product Does
  

During the exhaust stroke, the valve lifts from its seat so spent combustion gases can leave the cylinder. Once seated, it closes the exhaust passage, helping the combustion chamber retain compression.

Functions

• Opens the cylinder's exhaust passage at the required point in the engine cycle.
• Closes the passage by seating within the cylinder head.
• Operates alongside the guide, stem seal, spring, retaining discs and cotters.
  
  Technical Details
  
  
• Porsche component for the exhaust side of the valve train.
• Application engine capacity: 3.8L.
• The supplied diagrams specify 12 exhaust valves for each applicable engine assembly; this does not establish pack contents.
• 991 diagram model marking: A171.
• 997.2 Turbo diagram application identifier: A170.
  
  Symptoms of Fault

• Compression readings that are low or differ between cylinders.
• Recurring misfires or an uneven idle.
• Leak-down testing revealing leakage into the exhaust passage.
• Unusual valve-train ticking.
• Inspection revealing burning, bending or incomplete seating.

These findings require diagnosis and do not, individually, confirm that the exhaust valve needs renewal.

Why Replacement Matters

A valve that cannot seat properly can allow cylinder pressure to escape. Renewal may be appropriate following confirmed damage or as part of assessed cylinder-head rebuilding. With the head dismantled, examine the seat and guide, together with the seal, spring and retaining hardware, before deciding which supporting components need attention.

FAQs

• Which tests help identify valve leakage?
  Use compression testing alongside a leak-down test, then inspect the head to determine the underlying fault.
• Are twelve valves included?
  The diagram records the engine's valve count, not the quantity supplied with this product. Confirm pack contents before ordering.
• What else needs checking during head work?
  Assess guide clearance, seat condition, stem seals and spring hardware rather than renewing the valve without inspecting its surroundings.
• Is the model designation enough to establish compatibility?
  Verify the reference using the VIN and engine specification, particularly when production revisions may affect selection.