Engine is dead after less then 3 years of use

[mrbrian200]

On a side note regarding the PRV/PCV on the newer 3.2s. There seems to be a ton of information about this in the 'Audi sphere'. The primary issue stems from a tear or hole that forms in the PRV diaphragm.
Once the tear forms the engine runs lean resulting in upper cylinder and piston/ring damage. Somehow the way this system works the crankcase also becomes highly pressurized (external leaks, oil pushed past the rings into the combustion chamber). The design differs slightly on the application, for example some vehicles which utilize this Bosch type PCV system also have a second simple check valve in addition to the pressure diaphragm, on Turbocharged engines (maybe?).

Audi/VW have been replacing the original PRVs with a revised part. I'm not sure what the difference is, but an educated guess would be the diaphragm/spring mechanism is changed somehow to make it more durable.

I don't understand how Volvo's solution, synthetic oil, would remedy this. It would need to have specific additives/conditioners to keep the diaphragm from deteriorating. Which may or may not be present in various brand synthetic (or conventional) oils. At best synthetic might help keep the check valve clean (if used on the Volvos) and what looks like a narrow passage leading to a recirc vent open. Or is it restriction of this vent/passage that results in abnormal pressure which causes the PRV diaphragm to rupture?

Looking at pictures of the Audi implementations on different engines, not all designs would have this potential issue with crud building up and restricting a narrow passage. But they all appear to have issues with the PRV diaphragm failing.

[mrbrian200]

On a side note regarding the PRV/PCV on the newer 3.2s. There seems to be a ton of information about this in the 'Audi sphere'. The primary issue stems from a tear or hole that forms in the PRV diaphragm.
Once the tear forms the engine runs lean resulting in upper cylinder and piston/ring damage. Somehow the way this system works the crankcase also becomes highly pressurized (external leaks, oil pushed past the rings into the combustion chamber). The design differs slightly on the application, for example some vehicles which utilize this Bosch type PCV system also have a second simple check valve in addition to the pressure diaphragm, on Turbocharged engines (maybe?).

Audi/VW have been replacing the original PRVs with a revised part. I'm not sure what the difference is, but an educated guess would be the diaphragm/spring mechanism is changed somehow to make it more durable.

I don't understand how Volvo's solution, synthetic oil, would remedy this. It would need to have specific additives/conditioners to keep the diaphragm from deteriorating. Which may or may not be present in various brand synthetic (or conventional) oils. At best synthetic might help keep the check valve clean (if used on the Volvos) and what looks like a narrow passage leading to a recirc vent open. Or is it restriction of this vent/passage that results in abnormal pressure which causes the PRV diaphragm to rupture?

Looking at pictures of the Audi implementations on different engines, not all designs would have this potential issue with crud building up and restricting a narrow passage. But they all appear to have issues with the PRV diaphragm failing.