I just discovered a huge vacuum leak on my 1994 XJ6 and it seems that there is a huge crack in one of the crankcase breather hoses.
I looked on the Jaguar Land Rover Classic parts website and I believe the part number for this hose is EAC7447 which naturally is NLA.
This hose is a very strange shape and the ends are two different sizes. One end (smaller end) fits over a hose nipple on the 90° elbow leading to the throttle body and the other end goes to some sort of electrical heater unit. I went to a local parts store that I know has a large selection of various hoses hoping that I would find something close enough to adapt to this application but nothing was even close.

Since most of these critical parts have been discontinued I don't know how we will keep our care on the road in the future. BTW, I also noticed that the corrugated hose that connects the larger end of the 90° intake elbow to the inlet of the throttle body is also NLA from Jaguar. I can see this being a critical thing when these start to fail in the future.

crankcase breather hose diagram - item 6 is EAC7447 which is NLA.

Mass air meter and throttle body elbow - item 7 EAC9552 is the elbow

My hose from 1994 looks like this:


The crack in the hose can be seen here:

Big crack in hose

It fits between these two connections:

 

Nevermind, good news. I was able to find replacement hoses on ebay by searching for the Jaguar part number EAC7447
I ordered two of them just in case. I hope they are the right thing and fit when I receive them.
BTW, searching on ebay also shows the large corrugated hose EAC 6370 for the intake is also available from several sellers.
I guess the parts supply isn't so hopeless after all.

 

Yes, fortunately there are some more parts suppliers which can deliver what Jaguar can't. Even though I noticed that prices for some parts have increased significantly in the past 2 or 3 years.

In your case: since this is a 'solid' rubber part maybe it could be fixed by vulcanizing it, in case no replacement part is available

.

 

This is one really oily hose internally and if it has split, you could attempt vulcanizing it but I wish you luck with getting it clean enough. Easier to use two hoses and a union. That's what I did when mine split.
The URO corrugated hose from Rockauto, although a bit more light weight than the OEM is definitely the way to go if the air intake hose has deteriorated - and let's be fair, if you take it off for a annual TB cleanout/oil dump theres a pretty good chance it's less than perfect anymore, especially around those flanges.

I'd imagine even the Ultra-Power one would probably just fine also.

https://www.rockauto.com/en/catalog/...take+hose,6344