Inlet manifold oil - fixed (2.5 V6)

[JustBadly]

Running this Jag I noticed Oil collecting in the induction manifold when, if ever I removed the lower flap motor. This was a complete mystery to me since the manifold casting had no Oil feed! I finally tracked it down and it is the breather valve on the left valve cover. 

When the throttle is closed a vacuum develops in the manifold and the breather valve would shut. Instead the design of this is too aggressive and it fails to shut, causing a permanent air-bleed to the manifold. Result: condensation of Oil vapour.

The fix is to dismantle the PCV and fit new internals, controlling the valve with a ball-bearing. The bearing is placed on a hollow post to put it close enough to the valve hole that it will close given a small amount of suction. 

You will see I have a breather catch tank off the right valve cover, this is working as it should and no hoses have blown off the engine.

This fix is for the 2.5v6, the 3.0v6 has a different arrangement and might well be ok.