Hi all,

My 05 xj8l has 210,000 miles and sprung a major coolant leak. My mechanic pressure tested the system and thought the leak was coming from under the intake manifold.

in the quest to save $900 in labor costs, I’ve decided to attempt this job myself.

I could not find a detailed step by step thread for N/A 4.2 x350s, but I’m pretty sure these are the parts I’ll need:

Under Intake hose AJ811763
TB Return hose AJ89554
2x EGR Gasket AJ88560
Intake Manifold Gaskets https://www.ebay.com/itm/jaguar-xj8-...d=182671970732
TB Gasket
Metal Intake Manifold Gasket

I’m not sure if these are all of the parts I’ll need, and was wondering if anyone thought there was anything else?

Also, are there any other coolant hoses/preventative maintenance parts I might want to replace while the intake manifold is out?

Thank you.

 

Thermostat with housing, water pump, tensioner, with idler pulley bearing.
All come to mind, while your there.
Any hoses that look marginal, also comes to mind.

 

Do you happen to know if the coolant hose part numbers are the correct ones for an n/a 4.2?

 

https://www.jaguarforums.com/forum/x...on-s-c-149873/

 

I replaced the knock sensors when I replaced the valley hose.

 

That is something i missed, when there.
Any idea what they cost?

 

+1 on the knock sensors. Especially with there being anticipated coolant spillage which makes them angry.

AJ84433 - $58.25 list
AJ85676 - $132.75 list

 

This is in the back left part of the manifold.


So far, I’m making decent progress.

I’m having some trouble undoing certain connectors. Does anyone know how to discouple these?

 

I showed these to my mechanic, and he coached me on how to remove them.

Now, the only thing left to remove is the fuel line(s).

I bought a disconnect tool from harbor freight. https://m.harborfreight.com/3-piece-...not%20provided Would anyone happen to know where to connect it to?

Also, will I need special pliers to disconnect the hoses once I get the manifold off?

 

Spring clamps on my 04.
May need to open the jaws to their wider setting for the bigger end.
I have a set of pliers that are just a bigger size, that work great.
A gift from several years ago.
Long before the giver passed.
Appears like your progressing well.

 

I used the fuel disconnect tool on the other fuel line, but can’t get this line to come off and I feel like I’m not doing something correctly.

 

Your fuel line retaining clip is still attached.

 

How should I unattach it?

 

Look at your picture, on the other side of the connection.
A spring wrap around type clip, pry it straight up.
It has a string type wire on it.

 

Thanks. That was very helpful and I got it off!

Tomorrow, I’ll disconnect the manifold and inspect the hoses if it isn’t raining too terribly.

 

Be very careful with the Brake Servo Vacuum Pipe (or whatever it is called) attached to the back of the Inlet Manifold, both when removing the Manifold and reinstalling it.....Also, the Manifold Absolute Pressure Sensor is attached back there?

 

I was able to open the manifold today, but it is still connected at the back and I can’t seem to get it completely out.

In any case, I was able to lift it up enough to see that my valley hose had a giant inch wide tear in it. That explains everything...

Under the manifold, I found two brown absorbing devices, one filled to the brim with some liquid, maybe coolant. Does anyone know what these are, and what part number I can use to reorder them?

Also, I ordered the $79 upper intake manifold gaskets from ebay, but don’t see where they would attach to the manifold. It doesn’t seem like they are under the metal gasket, but that’s where I would guess they belong.

 

M A P sensor, & brake booster hose, like EsRay mentioned, need to be disconnected.
The manifold comes apart, those eight gaskets, then go inside, you'll see where.

 

To disconnect your Brake Booster pipe you need to peel back the silver-coloured heat protection and disconnect as shown in the bottom
right of this picture:


There are also two bolts securing the Wring Harness to the rear top of the Manifold and the Map Sensor must be unplugged. Be very careful when removing and refitting the Manifold - The Brake Booster pipe can become quite brittle back there!

The brown 'bags, are (I believe) for sound proofing and yours has probably become saturated with the leaking coolant?

 

Agreed would probably forget about, myself.