I need to replace the coolant hoses which run through the engine valley on my 2003 XK8 4.2 - I realise that to do this I need to remove the inlet manifold which probably also means taking off the throttle body. I've had a look and can't find any instructions about how to do this - can anyone help?

I did try downloading the JTIS in the hope that would help but it says it won't run on my machine which is running Windows 10 64 bit - if there is a solution to that is would be great.

Basically a run through of what I need to be unbolting and any parts I need to buy before starting would be helpful - I'm guessing some gaskets may need replacing at least.

 

The first part of this thread shows how to remove the throttle body.


https://www.jaguarforums.com/forum/x...val-how-96841/

 

I did this job, kinda hard to explain, sorta just have to start taking **** apart, PAYING ATTN to what you are doing even maybe taking pics on your phone as you go. You will need new gaskets form the Black intake plenum as you don't want to use the old ones over as they may cause an air leak and throw a code, restricted performance issue. The TB and the Elbow it is connected to has to come off. With ANY wiring and connectors HANDLE WITH care as you go as some of it can be a bit brittle. There are a few other hoses you will have t deal with, and since you are going as deep into this you may as well replace the octopus hose also, this would be the best time as it would be easier now with stuff apart then later when it is together.
For me this repair turned from replacing two hoses as you are doing to MANY.
the gaskets for the black plenum you are taking off JAG does not sell. Tonight I can get you the part and cost for them. Like 20 bucks a piece. You need two gaskets for the Intake and Intake elbow that you can get online or from a dealer. Torquing all bolts when you put it back together is wise, just done guess. There is also a vac like that runs under the intake also, replace it while you are there. Check all hoses for any bulges, if any are this would be a WISE TIME to replace them!
Be careful with the connectors as I said in and around the TB, just take your time, you will be ok. I did this same repair to my 03. Any seal you take out or expose, wise to jsut replace with new, specially since these cars are older and either have been just sitting around or have many miles. One tricky part is the plastic tube coming in from the pass side strut tower to the pass wide of the TB, that can be an issue part, if you take it out, you will have to replace an oring and a catch that holds it in the TB.
I will chime in more later, I am at work.

 

Thanks for the replies - looks like I need another trip to the dealer (I already got the hoses from them).

RaceDiagnostics, I think that must relate to an earlier car as mine doesn't have a throttle cable to the throttle body, it is electronic to that point. Useful information though.

 

Yes 03 has no TB cable but otherwise it is pretty similar in taking it apart. The TB is connected to the TB elbow that connects to the back of the Black Plenum. You CAN NOT take it all off as one pc, you must take off the TB then the Elbow.

 

Ignore the third post and look down to my posts below. My engine is a 4.2 the same as yours.

 

Thanks RaceDiagnostics - I'm now wondering whether to replace the heater pump whilst I have everything apart, the heater hasn't worked well for the last two winters but strangely started working fine when the weather warmed up (before going cold again!).

 

It makes sense to do it at the same time, you don't want to have to do it all again later. FYI, I reused the TB gasket and it leaked, so I had to strip it down and replace, so best to order a new one too.

 

Any gaskets, orings on these cars, one the stuff is apart better off replacing. Many stories here where folks reused them and had to go back in and put the new stuff one.

 

Thanks for the help everyone, job achieved today. I didn't do the heater pump in the end, really needed to get the hoses done today and didn't have chance to get one in time so I'll tackle that later in the year and hope that the weather stays warm enough for it not to be a problem for a while.

The valley hoses definitely needed doing, it wouldn't be long before the top one as seen on this picture burst - no wall strength at all and about twice the size it should be.

 

The valley hose that connects to the passenger side octopus hose, that hose on the valley hose connect to a tube, on that tube there is a smaller hose that goes up to something I forget, but that hose on my 03 was 3x its orig size and was ready to go at anytime. You may want to replace that while you have it apart just to be safe because it is not reachable I think with the car all back together.

 

Fortunately all the smaller hoses have been replaced recently, the one you mention was OK - it goes to the throttle body elbow - I had to remove it from there today. I assume you mean the one in the top right of this photo

 

yea that is the hose, it looks good. You going to replace the Tstat and all that? There is a vac line that runs under the intake, replace that.

 

did you find source to get the 8 green gaskets that go on the bottom of the intake?

 

How did you handle the black plastic tube that comes in from the passenger strut tower to the TB?

 

I replaced the thermostat and water pump whilst it was apart, didn't do the green gaskets but to be honest I don't think mine had any, I did put new manifold gaskets on though.

The black plastic tube was a pain, not quite sure what it does (mine is a UK RHD car so I had thought it might be the vacuum for the brake servo) but the sleeve which is in the TB wasn't good (one lug broken off) so I put it in with some blue hylomar instant gasket - I've been for a drive and everything seems to work OK so I'm happy at the moment.

 

The green gaskets I was speaking about are on the bottom side of the black plenum you took off the motor. 8 of them.

 

BRG,

That tube going from the TB to strut tower is the brake vacuum booster take-off. It's a PITA to get out because it's held in with internal clips. I just got mine out a couple of nights ago. With the TB off the elbow, you can see that tube protruding about 1/2" into the elbow cavity. I used a channel lock to leverage the tube out. It was a bit gruesome, and I'd thought I may have damaged the tube, but it's fine. Someone in here came up with 3/8" compression fitting solution for an improved connection to the elbow. I'm going to try that when reassembling.

 

Nice work Andy. Those hoses (and all gaskets and seals) were the next project before this summer. And then the Passenger side blew. Guess it's the next project, .... NOW!

;-)

 

I didn't separate the inlet from the plenum but there were no green gaskets where the inlet joined to the head - I cleaned all the surfaces before putting it back on so pretty sure I would have spotted them. There was a single gasket for each side which I bought from the dealer last week and fitted, there was nothing showing on the system at the dealer when I ordered the parts or I would have tried to order those too.