Repair Your Porsche Cayenne Air Oil Separator Without Replacing the Entire Unit
 
The KLA Performance Engineering Porsche Cayenne Air Oil Separator (AOS) Diaphragm is a cost-effective solution for repairing a failed air oil separator. Instead of replacing the complete assembly, this replacement diaphragm restores proper crankcase ventilation and helps eliminate common symptoms associated with a damaged AOS membrane.
 
A failed air oil separator diaphragm is a common issue on many Porsche Cayenne models and can lead to excessive vacuum, rough idle, oil consumption, smoke from the exhaust, and check engine lights. Replacing the diaphragm can restore proper engine operation while saving hundreds of dollars compared to a complete unit replacement.
 
Common Symptoms of a Failed AOS Diaphragm
 
If your Porsche Cayenne is experiencing any of the following issues, the air oil separator diaphragm may be damaged:
Excessive vacuum at the oil filler cap
Whistling or squealing noises from the engine
Rough idle
Increased oil consumption
Smoke from the exhaust
Check Engine Light (CEL)
Lean mixture fault codes
Crankcase ventilation issues
 
Features
Direct replacement diaphragm
Cost-effective repair solution
Restores proper crankcase ventilation
Eliminates excessive crankcase vacuum
High-quality replacement material
Designed for long service life
Helps avoid complete AOS replacement
 
Benefits
Save Money
Replace only the failed diaphragm instead of purchasing a complete air oil separator assembly.
 
Restore Engine Performance
Proper crankcase ventilation helps maintain smooth idle quality and engine efficiency.
 
Reduce Oil Consumption
A functioning air oil separator helps prevent excessive oil ingestion into the intake system.
 
Prevent Future Issues
Repairing the diaphragm early can help avoid additional drivability and emissions-related problems.
 
There are 2 versions of the 4.8L diaphragm. If your cap is closer to the front of the motor, it uses the 4.5L version (see picture labeled 3). If your cap is closer to the middle of the motor, it's the 4.8L version (see picture labeled 4). We've also learned that the 2003-2008 Cayenne Turbo and Turbo S will use the 4.8L version on the 4.5L engines regardless of where the cap is located.