Oil Filter Separator Box Diaphragm - P1 & P3 5-cylinder

This is the cute little diaphragm that goes inside the oil seperator/breather box assembly on most of the 5 cylinder P1 and P3 cars. When this diaphragm is compromised or torn it results in the famous "idle squeal of death" while stuck in daily traffic.

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 (indicated by part number 31338685 on the top cover) and the diaphragm has failed again, this is the diaphragm that fits 31338685.

For all P3 five cylinder Turbo (S60/V60/XC60/V70) and P1 five cylinder (C30/C70/S40/V50) from engine 3285662- onward.

Additional Keywords: FLAME TRAP SQUEAL PCV

Additional Technical Information

If your cap or spring are broken, consider our diaphragm + cap + spring kit, see Similar Products below.

Product Fitment Notes & Potential Issues

If you have a P3 (S60, V60, XC60 or V70) Five cylinder turbo model, then this is the correct part for your car.

If you have a 2006 or newer P1 (C30, C70, S40 or V50) model, this is the correct part for your car. 

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 from engine serial number 3285662 onward had the later style box with the 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 has a heater element connector then this is the correct part for that box.  If your box does not have the connector, please see similar products section on this product page for alternatives.