S Type oil leak
 

Any Jag techs out there
V8 S Type cam cover gaskets I have replaced them twice and a third time siliconed head the head surface.however they come back leaking again, The crankcase vent system is functioning as per tsb test any ideas this is baffling us :icon_shrug:

A Fix
 

Using a magnehely guage i found there is not enough crankcase vacume regardless what the TSB says so with screen and steel wool i built a restricter to get 3 inch pounds of water this resolved our issue hope it helps someone else out there upon request i can post a step by step

Thats why you dont "boreout" the part load breather

The part load breather is the correct size as per TSB

Bob im not speaking that yours is was might be, only that ive seen and heard people think you just drill it out. It is "supposed" to be a restriction

Oh Thanks have you ever heard of having to add a restricter i know this is not normal but a jag is a breed of its own and we have had several XK's and S Types but no XJ's

No it has a restrictor in the port of the cam cover, but you know how things wear with time and what worked when new on the engeering board doesnt meen it will down the road when older. Sounds like you fixed it