So Eurotoys has a $258 kit for Supercharger Duct Seals & Plates.

http://http://www.eurotoysltd.com/catalog/product_info.php?products_id=1272&osCsid=vhffrcl8t 80eqnquba7ul5a7a1

Since my car is 12 years old, with 95,000 miles, gets driven daily but mostly short distances, I am wondering how to tell if this needs to be done.

One mechanic quoted me $270 for labor on the lower pulley upgrade that I plan to do shortly so keeping the system healthy is on my mind as I plan to drive the car for years to come.

 

Unless you have reason to suspect they are leaking, then there is no reason to mess with them. They aren't really a maintenance item and with the part load breather, they will be well oiled on the inside and shouldn't dry out or anything like that.

I reused my 70k mile ones on the twin screw install and they hold 21psi just fine.

You could hook up a boost gauge to the port on the S/C outlet and check the pressure if you want to be doubly sure. On a stock car, it should be 13psi, give or take.

 

The seals/fixing plates for the 4.2 engines have an additional protection to avoid that the ducts can be sucked in compared to the 4.0. Going from full boost on a stock 4.0 car you go from +11,6 psi to -11 psi vacuum when coasting to give an idea.

As far as I can see on the web site, these are the standard Jaguar 4.2 parts, they will fit the 4.0 cars and is recommendable if you go much higher in boost for just in case.


Here are the partno's:
AJ86926 1x
AJ86925 2x
AJ86927 1x RH
AJ86928 1x LH


Here an example where you can get it all for about $210.
http://www.gaudinjaguarparts.com/par...gramCallOut=14