PCV Diaphragm, Spring & Cap Kit, 2.4i & T5 5-cylinder - P1 P3 S40 V50 C30 C70 P3 S60 V60 XC60 XC70

The PCV (positive crankcase ventilation) system is responsible for getting rid of cylinder combustion blow-by and oil vapors inside your engine. When the engine is running, a little bit of air escapes past the pistons in to the "guts" of the engine, and it's the PCV system's job to suck this blow-by air out of the engine crankcase, separate any oil vapor out, and recycle the air back in to the intake. 

On P1 and P3 5-cylinder engines, the amount of vacuum the PCV system draws is controlled by a spring-loaded rubber diaphragm on top of the combination oil filter housing & PCV box. Time and heat cycles will eventually break down this diaphragm, and once it tears you get a nice squealing sound from your engine bay when idling at a stop.

This squeal is more than just an annoying noise: since the diaphragm regulates vacuum, a torn diaphragm will cause too little or too much crankcase pressure, eventually damaging seals and causing oil leaks. Not good!

This kit includes a new diaphragm, as well as a new cap and spring in case you lose or damage yours during removal.

Additional Keywords: SQUEAL MEMBRANE SEPARATOR

Additional Technical Information

Installation is pretty straightforward with the ECU/airbox housing removed: tap a flathead screwdriver in to the gap between the cap and the PCV box and work your way around to pry it up.

When installing the new cap, make sure to align the notch on the PCV box (red, below) with the tab on the cap (blue, below)

Product Fitment Notes & Potential Issues

Fits all 5-cylinder T5 P3s (S60, V60, XC60, XC70) and all 2.4i and T5 P1s (S40, V50, C30, C70) from 2006 and up.

If you have a 2004.5 or 2005 P1, you need to check your PCV box to see if it's the updated style with a PTC electrical heating element, circled below.

• All P1s with engine serial number 3285662 and up have the updated box and can use this diaphragm kit
• Many early P1s have been updated to the later style PCV box
  • Early cars with the updated PCV box may have the exposed PTC connector, but with nothing plugged in to it