2005 XJR. First off, this "valley hose" replacement was a nightmare. Everyone said, "It's not an easy job" and "It will try your patience"... what they did not say is that it will take much longer than expected, require tools that you probably don't have, and will scratch the hell out of your arms reaching into places where you didn't even know your Jag had places. I encountered all of the issues that everyone else did, and I replaced all the hose and seals along the way. The central valley hose was the culprit and had the typical failure up front where the hose graduates from a smaller size to a larger one. It wiped out my knock sensors when coolant got on them, so they got replaced too. Things went together much more easily than they came apart or were removed, but that brings me to my question. It's about the supercharger outlet pipe that sits on top of the supercharger and splits the charged air into both intercoolers. It has a small diameter vacuum line that comes off the back and connects to something. When I pulled the outlet pipe (splitter) out, the small hose just popped off of whatever it was connected too on the other end and came out still attached to the outlet pipe. It's time to hook it back up and I have no idea where the other end goes. Any ideas? Thanks!

 

A bit of forum sleuthing leads me to believe that this is to connect to a Fuel Pressure Sensor. I've located what appears to be the Fuel Pressure Sensor, but the diameter of this hose is very, very tiny, so I must be missing the connector that goes between it and the sensor. It looks like it connects to an "L" shaped elbow piece that comes off of the side of the sensor, but that pipe has some sort of plug or connector in it and is at least 8 times the diameter of my mystery vacuum line.

Here's the forum entry were the problem was the opposite end of the same hose, where mine is still connected. No photo provided of the Fuel Pressure Sensor.
https://www.jaguarforums.com/forum/x...m-line-135127/

 

Best bet may be to look at parts diagrams till you find everything.

 

SOLVED! It turns out that the plastic barb or nipple that the hose was to attach to had broken off inside the hose. The joiner left sticking out of the Fuel Pressure Sensor elbow was flush on the open end with no way to attach to it. I removed the remnants of the old joiner from the elbow, fished the broken off piece out of the vacuum hose, and found that the broken piece was just long enough to connect the two hoses on its own. The plastic joiner was very brittle, and I suspect that the vacuum line snapped it off about 6 months ago.... when I started getting an intermittent error code across both cylinders that suggested I had a small, occasional vacuum leak.

My forearms and hands are scratched from installing the EGR and Intake Elbow, but the job is done. One test drive, rather spirited towards the end once my confidence was up, and no leaks or engine codes.

Next project: Replace the upper control arms. I've already replaced the front air struts twice, so this shouldn't be too much trouble. The original air struts lasted 100K miles. The second front pair lasted 12K. The third pair show signs of losing pressure (and a hissing noise) after only 10K. They only leak in Winter, which is rather mild and shortlived here in Austin, TX.

 

The life of the replaced air struts looks very small to me.
Did you use new OEM parts or refurbished sets?
I have put a set of new Bilstein B4's on the front that I hope will last much longer than 10k!