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I had read Mike's excellent series of posts and mag articles about the valley pipe and had ear-marked it as a job to do in the future when it suited. However in November or may be December I started getting the 'low cooling fluid' warning and when I started using more anti-freeze than petrol, I decided I should do something about it. The only problem was that I couldn't figure out where the leak was coming from (even though I'd read the articles). I had the car up in the air one day, engine running and absolutely no sign of a leak anywhere. After about half hour of poking around underneath trying to hunt down another problem, that being the suspension noise, I suddenly felt a few drops down the back of my neck. At that point it finally became obvious that the fluid was leaking from the top of the V down the passenger side towards the back of the engine. Only once the supercharger is remove you can appreciate the amount of space there for water to accumulate and also a rather nice sound deadening sponge that also soaks up the fluid.

One feature of these cars is that it is extremely difficult to see anything without dismantling things. Most of the cooling hoses are to the front of the engine, but to see them you need to remove the header tank and the air ducting. To see anything at the back of the engine, the wipers and scuttle cover and various plastic bulkhead covers need to come off. Certainly the more you remove, the better access becomes. If you haven't removed the header tank before, there is a notorious spring clip that locks in place the main outlet pipe. This can be tricky to remove and is easy to loose! Its also a little tricky to access until the head tank is out.
Metal clip just visible

So the first steps are to remove the header tank and air ducting - both sides of the air filter - and this includes unplugging the MAF sensor. Then remove as many hoses as you can to the front of the engine and then the supercharger driver belt. This comes off reasonably easily if you can get a 1/2" square drive in to the tension arm, squeezed by the oil pipe. There's really no room there to use a ratchet drive and 1/2" adapter. While I was there I decided to replace the other drive belt too. This requires a different size square drive, but access is somewhat easier.
Some hoses removed

So while tackling the job of replacing the pipe, I did a number of other jobs too. These included:

* Valley pipe replacement
* Replacement of both the small pipe between the throttle body and EGR valve and the pipe from the EGR valve back to the front of the engine.
* Both drive belts renewed
* Water pump renewed
* Supercharger oil changed and back bearings greased
* Air inlet manifolds modified with jets for future direct injection - most likely LPG, but could be something more exotic!
* Another larger diameter hose replaced between engine and rear of thermostat housing

The next steps involve removing the wipers and scuttle cover. I couldn't initially figure out how this come off, but you just have to pull it at 90 degrees to windscreen with enough force to overcome the clipping mechanism. Then remove the plastic cover around the brake servo, the plastic bulkhead covers and the bracing bars. A relatively large torx drive is needed for these and so I had to go and buy one for the job.

The intake to the supercharger comes off without any problem. This allows you to see into the supercharger and also reveals one of the pipes and a vacuum hose.

To gain access to the components at the back of the engine, you really need to kneel on a board on the radiator and cross member. The throttle body comes off reasonable easy, but with the normal problem of removing the hose clips in restricted areas. One of these hoses is the other end of the valley hose.
There's a few electrical connections too and the vacuum 'thing' to the left of the throttle body needs to come off too. You can see in this photo that the bulkhead covers and bracing bars are removed.

The really tricky step is to remove the EGR valve from the intake elbow. This is after the hoses are removed - tricky too. I used very long-noise pliers. Do not remove the screws on top that are easy to access. This can lead to greater problems and needing to replace the EGR valve if you break the internals.
I gained access to the 'correct' screws with long extension bars and a flexible drive through from the brake servo area. You should just be able to see the socket - I think this is a 8 mm one. Most screws seem to be 8mm and 10mm and the torx screws are mostly the same size, but I don't recall quite which size. A new EGR valve gasket should really be used.

With the EGR valve removed, then the elbow can be taken off. There are 4 screws holding it to the supercharger. These can be removed OK. However there are another 2 screws attaching it to a bracket. These are really difficult to access, but luckily in my case they hadn't been replaced at some point in the past. Lucky!

With the elbow gone, this screw can be accessed..
You can see the fluid in the V section and the bracket is also just visible behind the socket. I removed this and discarded it.

Finally with the supercharger removed - only three screws - then the valley pipe is visible.
Here is the pipe off the car:
And the point of failure is just visible - a tiny pin-prick in the larger section part, right at the end of the pipe.
Its difficult to believe this was leaking so much fluid!

Here are a couple of views with the charger off the car.........
The large hose in the middle was one of the others that I replaced.

With the charger off the car, I was then able to take the inter-coolers off. These come off very easily, but there are a number of torx screws hidden by the charger and only accessible with it removed.
I don't have any pictures detailing removing the injectors, but I had a struggle getting these out and never did figure out how to release the 'quick' connect (may be slow-connect!!) in the fuel line to release the injector rail from the fuel supply line.

With the injectors removed, the intake manifolds came off easily. This delayed the job by a week while these went away for modifying.

On putting this back together, I managed to get an o-ring at the top of one of the injectors quint. This meant that when I finally had everything back together, I had a petrol leak and everything had to be stripped down to the same level again. At least this time it came apart a lot easier. I think I managed to get it all apart in about 5 hours and did the complete job over a weekend. If anybody strip things to this level and wants to check the integrity of the injector rail, then there is a valve that you can put a standard tyre inflator on and check for leaks. I only tried this second time around and am really not sure whether it is a good idea or not to inject air into the injector rail, but at least at that point it gave me the security of knowing the o-rings were sealing.

Excellent material, Roger.

You went two stages further than me. Your genius was to remove the brace bars and also the section around the brake servo, the rear of the throttle body and the pollen filter. Had I done that, (by that time I had reached the limits of my own physical endurance) I would possibly not have had to send my car off to Jagcare for them to finish what I failed to achieve. In addition, I did not take the intercooler bricks off. I had the AJ88047 inlet manifold gaskets to hand but as the car was out of my hands and I wished to keep what became a fairly large invoice to a minimum, I decided not to go that one stage further.

After my saga, I wrote an in depth article for the magazine which has yet to be published. I was able to send that to Roger in the hope that it would be useful to him as he tackled his own project. Now, with Rogers additional insight and hands on experience, we can edit that article again and add more to my original text.

Mike K

So while I had the supercharger off the car, I thought I would give it a service. This was following the very helpful advice of Mike and also Lawson Smith of Powerhouse. I think an oil change can be done with a struggle with the supercharger in place, but it is advised to re-grease the rear bearings too and this can only be done on the bench.

The front of the charger comes apart easily by removing the screws that can be seen missing in this picture. When pulling the front off it is advisable to take note of the position of the drive dowels inside - difficult to see as it comes apart and too late once in two bits.

I had a question about which side of the spring the dowel acts, but Mike and Lawson were able to help me out with that. Here are a helpful couple of photos Lawson sent me:
Here's a shot of the internals with the rear bearings just visible.
So many thanks to Mike for assisting remotely and providing invaluable advice and also too to Lawson for help with the supercharger.

Well done Roger - as we say down here in Wiltshire "proper job!"

Hey I have a 2004 XJ8, no supercharger. My car was dumping coolant and at first I thought it was the water pump, however after replacing that the problem persisted and I came to realize there was a crack in the valley tube. I am not by any means knowledgable with Jaguars, I'm learning with the car as I go. However I can not seem to find the part number for the valley pipe anywhere. Does anyone know what it is or where I can find it? I've called several dealerships and they've been no help what so ever, one even told me 'sorry, we dont carry parts for cars older then 10 years, look online"

Any help would be much appreciated

I think your dealership is being lazy. Jaguar do sell parts for cars older than ten years.

I would suggest you contact a good independent UK based Jaguar parts supplier for help and identification. XJK are popular with many of us here and their delivery service is very fast. Have your VIN identifier to hand when you contact them. The last six digits are what you require ie G44362. This can be seen in the lower right hand corner of the windscreen on the plate set in the top of the dash panel.

Mike K

Here's my venture into valleyland!

Supercharger fitted with 10% pulley (after mucho filing and grinding) and doughnut coupling to replace the springy one.

Also fitted initial hoses for LPG conversion (drilled and tapped into inlet manifolds).

Still much to do, but these dark nights don't help - no garage!

Well worth doing, Steve.

The snout work is tedious without a four jaw chuck and lathe. I did my conversion on the car with flies, a power file a mirror, a vernier, size caliper and garnet paper...that took nearly four hours. Much easier if the job is on the bench.

The dough nut coupling is a fit and forget unit and is vastly more robust than the rather quieter OE unit.. However, DO EXPECT to expect the coupling to rattle at idle speed. Lawson warned me about this. What you are hearing is the back-lash between the driven and non driven gears on the charger.

Your next stage is porting out the throttle body elbow. Remove the silly constrictive ridge below the throttle body. Gas flow the elbow internals and lower the bottom long edge of the elbow by about 6mm. Ramping of the elbow will be needed and a matching ramp created upwards into the charger. The rubber/metal gasket will also need to be lowered. A load of metal around the rotor inlet ports can be taken away. The edges of the pressure plate can be cut back and flowed. A nice finish to the plate can be created. Also port match the cow-horn manifold to the charger case. Clean out excess metal in the cow-horn by-pass throat. Loads can come out which gives a nice smooth pick up as you come out of a low vac condition after idling or over-run. The more metal that gets removed, the better the car will run and perform.

Mike

Thanks Mike - I appreciate the tip.

Do you know what the official name for the valley tubes are? I'm assuming 'Valley Tube' is just the name its been given but do you know what the official jaguar parts name for the tubes is?

It is commonly known as a alley pipe for obvious reasons.

The pipe runs from the rear of the thermostat housing through the valley, around the lower rear of the throttle body, but I can`t recall what it links to. Steve or Roger might be able to help on that as well as providing a current part number. At the thermostat end, the pipe is distinguishable and notable in that the first two inches have an expanded end to fit the thermostat housing. It is that expander that splits, cracks and leaks given time and mileage. The heat from the housing seems to destroy the rubber pipe at that point. The majority of the pipe will be perfectly usable for further use. I`ve always wondered if it would be possible to use a joiner withing the good remaining part of the pipe and then obtain a silicon expander from Viper. Silicon pipes last longer in high heat conditions than do rubber components.

Mike K