EGR valley hoses NON S/C
 

I have found lots of threads and photos of valley hose replacement for the S/C 4.2, but not anything on the Naturally Aspirated engine.

On my vehicle, the hose running from my throttle body (bottom right) under my intake is deteriorating. The FSM and dealer part catalogs are showing multiple different part numbers for the same "EGR to TB hose." Anyone have any good photos or can point me to the correct part numbers?

I also assume there is a return hose from the EGR to the front of the engine? If I'm pulling the intake I want to get all the hoses necessary at one time. The service manual is not clear on what hoses go where physically on the engine.

Thanks for any help,
-Michael

Some more poking around under the hood, turns out this hose is not part of the EGR, and I'm not sure if it even goes under the intake.

See the photo below with indicated hose. The EGR hoses are completely separate--those are up front and out in the open. This hose goes from the TB outlet then disappears under the intake. The FSM indicates it should go back to the water pump. I can not see where it's going.

Is it possible this is serviceable by just removing the throttle body?

https://cimg5.ibsrv.net/gimg/www.jag...14cb0f90dd.jpg

After more searching around speaking with some experts, I have the answer to my question.

On N/A 4.2L the TB coolant return hose is the only one under the intake. Part no. AJ89746. It loops around and connects to the front of the block behind the tstat. Part has been ordered. If there's any interest I can take a photo when I get to replacing this.

Here's an example of the part: JA-AJ8-9746 - Cooling Hose Throttle Body Return; 4.2 S-Type, XJ8

Sorry I didn't see your post earlier...as I did know that was a coolant hose from changing out my TB. Still good info...would appreciate the pics as to where that hose ends up and if it can be replaced with the intake on.

I just had a hose go - coolant pouring from the back of the engine compartment. Did you ever run across any information on whether there IS a valley hose and write-up for replacement on the NA x350?

There is definitely a hose under the intake on the NA 4.2L. No write up that I have found, but should be fairly straightforward. This hose appears to deteriorate faster than the others--all my other coolant hoses are in perfect condition, but this one is swollen and cracked near the TB nipple.

From the FSM:

disconnect all the electrical connectors from the injectors/sensors
loosen EGR from the throttle body
Disconnect fuel line from the fuel rail
I plan to remove the throttle body from the intake
Remove intake and fuel rail as an assembly

I will post more details once I get around to doing this job. I am replacing the TB and intake gaskets when I do this job. The EGR valve appears to have a metal gasket that does not get replaced.

Here is the hose in question. AJ89746, about $13 from Jaguar. Still wonder why the cooling system on these cars looks like a 10th grade science project... the whole thing looks like a kludged together afterthought.

https://cimg5.ibsrv.net/gimg/www.jag...6738798a3e.jpg

I need to correct my previous post--the hose in the photo and the part number are not correct. I inadvertently received the hose for a S/C 4.2 from my dealer.

The correct those for the N/A 4.2L is part AJ811763 and looks like this:
https://cimg6.ibsrv.net/gimg/www.jag...be65265386.png

Replaced this hose last weekend, only was able to take a few photos along the way. Was not terrible, but definitely made use of a second pair of hands when removing the intake.

I mostly followed the instructions in the FSM. Lots of electrical connectors and plastic clips to remove. The intake stays together with the fuel rail and injectors. I bought the following parts:

2x intake manifold gaskets (these are metal)
throttle body gasket
new hose

The EGR valve has a small metal gasket that was not replaced. Make sure you order 2 of the gaskets, Jaguar sells them individually. My dealer sent me just one and I ended up having to reuse one of the originals. No issue so far, but not ideal after all the other parts went on.

Ensure you blow out all the dirt and debris sitting on the manifold/head because it will all fall into your intake valves when you move the manifold. When removing the intake, pull out slowly, as there is the brake booster hose and a MAP sensor on the back of the manifold that has to be disconnected. Likewise it helps to have extra hands to reconnect while you hold the manifold for reinstallation.

You need a 1/2 inch quick disconnect tool to remove the fuel line from the rail. Of course the cooling system should be drained first, but expect a little coolant from the hose when you remove it from the block. It will just drain out the back of the valley.

Clean all the manifold mating surfaces well before reinstalling. Just a rag and solvent--don't use a razor blade on the aluminum.

https://cimg3.ibsrv.net/gimg/www.jag...9777b706b3.jpg

New hose (throttle body return hose from Jaguar, see part number in post above)

https://cimg8.ibsrv.net/gimg/www.jag...9186899bb1.jpg


https://cimg1.ibsrv.net/gimg/www.jag...778f79b3a7.jpg

Great write up!

We're ther other issues, or did you have to pull the manifold just to replace the one hose?

Man that hose is made just like the SC version! Did you get a leak in the short fat section of the hose?

That's where about 90+% of the SC engines hose fails.
.
.
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Nothing else was currently wrong, just that hose. Also used the opportunity to clean the TB, replace some other coolant hoses, change the tensioner pulley and drive belt while it was easily accessed. Still need to do my idler pulley, but that will have to wait for another day.

No leaks, but the end that connects to the TB was swollen and cracked. You can kind of see this in Thread #2 above. I had never even noticed this hose before. If the dealer didn't point it out I would have gone blissfully unaware until it did pop. There's no air flow under the intake, so that hose ages much faster than the others. The larger section was also swollen, so either could have been a leak in short order.

Now that,s interesting
 

On my hose failure, the fiber reducer had failed, and then the un reinforced small section hose at the bend into the Throttle body failed.i.e burst.

The above was a consequency of the overheating due to the thermostat housing failing. S type v8 2006 V8 NA.

any additional feed back on this.

Recently posted on the s type board hence digging it up.

Pics
 

Never mind didn't see the entire post! Looks like same 4.2 S Type but my hose to TB is harder to get right under TB! I'm hoping the same for my car cause mine is leaking severely from behind what seems the TB! Thanks for help

That little hose under the manifold
 

Mike,

Huge help on identifying this hose. I too have seen dozens of poorly drawn parts diagrams and endless photos of the wrong hose. Mine sprung a small leak that originally got me thinking it was the water pump. With the plastic manifold cover on, it drips into the same area as the water pump would leak.

Appreciate the heads up on avoiding getting dirt/debris into the intakes when pulling the manifold. Likewise getting all the ancillary gaskets and taking advantage of the opportunity to renew some of the other parts while the manifold is off.

Major thanks. It's been two weeks research to finally find the right part and pathway forward.

Best,
Daniel Orbis

Sorry I responded late to your post. Finding the correct hose is not easy. I sourced it from SNG Barratt (as well as other hoses and theromostat) and they used my VIN# to assure I got all the right hoses as there are variations. So for those in the future looking for the right hose - make sure your part source asks for your VIN.

My approach to replacement was to lift the intake manifold up, lower in back and higher in front. As I was replacing the thermostat and related at the same time all the front pieces were already off. I had more than enough space to work with to disconnect and replace the hose as well as replace the intake manifold lower gaskets. I did not remove the intake manifold - just tilted it - leaving most everything in back attached. I did use some sockets in back to keep the rear of the throttle body sufficiently elevated while I worked - I suppose a properly sized piece of wood would have been more stable.

So if any one wants to go this method - with the front pieces off already to change the thermostat/housing - one only needs to remove all the intake manifold bolts and any other restriction so it is free to tilt high in front and about an inch or two in back. Took an additional hour at most.

Hi mate,

Currently I am also suspecting valley hose leakage on my NA 4.2 XJ8. As mentioned in your post, the gasket for EGR should also be replaced for this job. Not sure if you can help to provide the part number?

Sorry that I am still new to my Jaguar and really need some help on this.

Thank you.

AJ88560, Gasket - EGR

[QUOTE=mhamilton;1308837]

The FSM and dealer part catalogs

Dear Michael,

What manner of inexplicable (to me, anyway) jargon is FSM, please? Something Service Manual?

I think you owe Michael an apology. FSM = Factory Service Manual. Stop being so quick to judge others. (SMH)

Box, I certainly would not want to 'judge' Michael - He has been of enormous help to me on numerous occasions. However, I am at a loss to understand how my comment is judging him? As I have said, the only person FSM appears to be inexplicable to is me!
The only person being so quickly judged here is also me...….
FSM is not in the Jargon Buster.....