2001 S-Type 3.0L V6

Tools needed:
8 mm deep well and regular socket
10 mm socket
knuckle/elbow piece to access back plenum bolts
Small screw driver to remove injector harnesses and hose.
Patience

After a lot of searching through these forums and my engine bay, I have finally found my vacuum leak.

It was a pretty big one that took me forever to find. I ended up replacing the upper and lower intake manifold gaskets, which brought me right by the leak, but I never saw it. It's a small, black hose in the middle back of the engine under the fuel rail.

There's here and there talk of it on these forums, but it all sounded like they were talking about the hard plastic lines that run under the manifold, not the soft one that I found.

This is it's general location. Easy enough taking the plenum off and setting it aside. Don't break the hard plastic lines, and careful when tightening it back down so as you don't strip out the brass fittings underneath. If you do, I used a fair amount of red thread locker and tapped it back in, let it dry, and finish assembling.


This is a closer shot of where the line is:




When taking off the fuel rail, careful not to break the fuel pressure sensor at the back of the fuel rail. And when putting the injectors back into the lower intake and the fuel rail back onto them, apply a small amount of oil to the rubber o-rings so they don't tear when you put them back.
The hose is under the circled injector.
Make sure to keep the color coded injectors on their correct sides when reinstalling.


Here I have the right side lower intake removed so I could better access the hose. It's a tight squeeze regardless; taking off the lower intake gave me some more room to work with.
I had to use a small flathead screw driver to slowly and carefully work the hose off these plastic fittings. It's too tight of a fit to get my hand in there. And I didn't want to man handle it for fear of breaking more plastic parts.




This is the culprit of my vacuum leak. Black soft hose at the back bottom of the intake under the fuel rail. I could hear the vacuum hiss, but impossible to find. My final look for this, I had pulled the fuel rail (again), reached down and felt the hose and felt the hole in it.
I didn't go to the Dealership to get a new hose, I just took the piece to Napa, told them I want to recreate this hose. They helped me match the size of the hose, I took the new hose home and cut it to size. Remember, it's easier to make it bigger, and cut a second time, instead of making it too small and adding hose.


Happy Hunting!

 

Yep, that's the one everyone with that era 3.0 engine has to replace - witness the endless threads already on here!

 

+1 Breather elbow, which is a very common item to replace along with the IMT o-rings.

Thank you for the detailed description and photos.

 

hondakillah,

Thank you for taking the time to photograph and post your helpful instructions!

Cheers,

Don

 

Does anyone know if the X350 v6 3.0L have this elbow as well?
I have a serious vacuum leak but cant trace it have done IMT rings and checked hose but zilch as yet?
I know the v6 isnt an option across the pond but hoping someone will chip in?

Joe

 

Excellent post, thanks for sharing

 

Nope it does not. This may help though:

https://www.jaguarforums.com/forum/s...ics-faq-52720/

 

Thanks Joyce I did wonder why the part didn't show when looking at sites with x350 part lists.
Gonna strip out the upper/lower inlet manifold at weekend and see if anything shows on seals.
Only other area I haven't looked at closely is the purge line and valve?

Joe

 

Just to give some closure on my vacum leak.
It was caused by Valve seat recession possibly as result of using LPG without valve saver lubricant.
Ended up putting on 2 used heads.

Instead of chasing all of the normal areas for vac leaks wishing I had done a compression test a lot earlier in diagnosis?

Lesson learned.

 

Does that breather elbow under the lower intake manifold affect a specific cylinder as No. 5 with DCT p0305 ?

Regards
M
Jag S-type 2002 Petrol 2.5 v6

 

did your leak sound have different pitches at different engine loads?

 

No my symptoms from memory were fluctuating idle and vac readings all over the place

 

Most vac leaks can't be heard but do cause problems.

Not that this particular (LPG-converted) car had that as the main problem.

 

Hi

Which Codes did you see associated with this issue. ? I have P0171 and P0174 No 1 and No 2 bank too lean. ie too much air.
it has become a nuisance and whilst I do not get an Engine light or limp home mode - it is rather annoying.

Did you also replace the IMT valve O rings at the same time?

Any guidance would be gratefully received.,

Jaguar Growlers unite ! LOL

rgds

Stuart

 

Took plenty of the time and patience as warned but just replaced the lower breather elbow on my 2000 S-Type 3.0 in 2026. Thank you for this post, it helped a lot. I had a worse time since one of my bolts snapped in half taking off the lower manifold. Was able to drill it out and retapped it successfully. Let me know if anyone else is attempting to do the same thing, I have plenty of pictures. Also, I will add that I was able to do it without taking any fuel injectors out and just holding the fuel rail off to the side.

 

Ooh, nice pics. I don't remember seeing this thread before.

For anybody else about to tackle the rubber elbow replacement, please also see my experience here:

https://www.jaguarforums.com/forum/s...rly-v6-264531/

I wanted to pass along the tip to loosen the fastener on the back of engine, securing the metal elbow. Don't remove the fastener, just loosen it. This give you a little extra play and makes it much easier to install the rubber elbow.