Oil Filter Separator Box Diaphragm, 2004.5 to 2005 - P1 S40 V50

This is the cute little diaphragm that goes inside the oil seperator/breather box assembly on very early P1 cars. When this diaphragm is compromised or torn it results in the famous "idle squeal of death" while stuck in daily traffic.

This diaphragm fits original oil seperator boxes used on engines up to -3285661.

There was a chassis break early in the P1 cars but any cars that have had PCV dealer service are likely updated to the later style. If your early car has been updated to the later style box it will be indicated by later part number 31338685 on the top cover. if your early car has been updated it will use 140065 instead.

Product Fitment Notes & Potential Issues

IF you have a 2006 or newer P1 (C30, C70, S40 or V50) model, this is not the correct part for your car.  Please see the similar products section on this product page for alternatives.

If you have an 2004-2005 P1 (C70, S40 or V50) model, you need to read further:

There are two styles of PCV oil separator boxes that could be fitted to these early models and they use different diaphragms that are not interchangeable.

P1 five cylinder models up to engine serial number 3285661 did not have a heating element from the factory.  

Earlier cars can have the later style separator box if it has been replaced at some point so you need to verify what is installed on your car.

This is most easily identified by checking for the heater element electrical connector on the oil separator box. The later box has an electrical connector which may or may not be wired to the engine harness.  Whether the connector has wires plugged in to it is not the issue, it's the style of box that matters.

If your oil separator box does not have heater element connector then this is the correct part for that box.  If yours does have the heater connector, then please see similar products section on this product page for alternatives.