Yes the 6.0L XJS did have the same bleed system as the 5.3L. It was changed in the XJ40.

The system is basically well designed. The header tank has pump suction applied to it, the radiator bleeds back to the header tank purging air from the top of the radiator - this is how it's supposed to work.

The problem I see - the header tank is connected to the top of the x-over pipe which also has pump suction applied to it, both are then connected to the top of the radiator preventing air being purged back to the header tank, or worse sucking air from the top of the x-over pipe back into the radiator. This could possibly allow air to remain trapped in the top of the radiator - not a good thing.

One other thing is the outlet of the heater matrix is connected to the input of the water pump, possibility of hot water back into the engine without passing through the radiator.

WJ's solution - remove the connection from the x-over pipe to the radiator (ie banjo bolt) and connect the top of the radiator to the header tank ONLY. This will purge air from the top of the radiator due to pump suction on the header tank. Re-plumb the outlet of the heater to the input of the radiator.

 

Quick Update for Daim: How I cleaned my Injectors

(1) Removed the Fuel Rail with All the Injectors attached.

(2) Removed the FPR's

(3) Turned the Fuel Rail upside down on the Bench and filled it with Wynns Carburetter Cleaner from an Aerosol Can. (as much as I could)

(4) A Female Airline Tail was loosely screwed on to the Thread where the FPR came off.

This was deliberately Screwed on loose so it leaked Air, as you only need very low pressure.

(5) Then I connected my Compressor to this Female Airline Tail (which seemed almost made for the job)

(6) Adjusted the Compressor to Minimum Pressure but Did Not Switch it On. (YET!)

(7)Found a Spare Injector Plug and fitted the ends with small Crocodile Clips, not needed if you have two pairs of hands but otherwise it makes

things a lot easier.

(8) Got a 9volt PP9 Radio Battery

(10) Switched on the Compressor (with the Female Air Tail leaking Air) because you do NOT want to build up any Pressure in the Rail.

If you were able to blow into it (don't try that at home) then that would be enough and you can also Control the Air by putting your finger or thumb

over the hole where the other FPR came off.

Too much Pressure or a build up of pressure, could blow one of the Injector Tubes off the rail, so you need to 'Freestyle' that, until you feel its right.

(11) Connect one of the Crocodile Clips to the (-) Negative Terminal on the Battery, with the Spare Injector Plug on one of the Injectors

(Start with the 1st one at one of the ends) so you don't lose count and miss any.

As you are Cleaning the Injectors one at a time.

(12) Tilt the Fuel Rail up on its side, or put it in any position so you know that the Injector you are about to Clean has some of the Wynns

Carburetter Cleaner in the Injector Hose.

(13) Take the other Crocodile Clip and then just Dab it on the (+) Positive Battery Terminal of the PP9 Battery

(DO NOT CONNECT IT PERMANENTLY!) Just give it a One Second Dab of Power.

Any more and you could burn out the Coil in the Injector (so bear that in mind)

(14) It should Spray Straight away if all is ok.

(15) Rinse and Repeat with all the other Injectors. (Keep the Fuel Rail Topped up with Cleaner)

But what do you do if One or More Injectors doesn't want to Spray?

Start by taking Comfort from the Fact that Mechanical Failure is Rare.

So turn the Injector on its side so the Tip of the Injector is Facing you and you can see the needle in the Middle of the Tip.

Then get the Aerosol Can of Wynns and Blast the Metal Tip Head on with the Carburetter Cleaner, at which point you should be able to hear the

needle 'Click' as the Blast from the Wynns Aerosol Can, 'Should' push the Metal Needle back into the Tip against its Spring.

Then Try it again with the Battery (Providing you heard the needle click back) it should 99.9%.

If it doesn't then Blast the Needle with the Wynns again and maybe again after that.

If it still won't play then start Tapping the Metal Part of the Injector with a Small hammer and then Try Squirting the Needle like you did before.

When I did mine I had to give a couple of Injectors a One Second Dab of 12volts instead of 9volts

plus more tapping with the Hammer and Squirting with the Wynns.

Don't give up be persistent and unless you are very unlucky, you will have them all Squirting in no time at all.

You Can buy a Hose Kit which will cost about £100 but if I was replacing the Hoses, then I would just buy a length of Injector Hose and then cut

the Hoses to length and even make them shorter as Grant has done.

Then you will need some Injector Seals, that slide over the Injector Nozzles to Seal the Fuel against splashing back from the Manifold.

These are very tiny Square cut 'O' Rings about £24! for 12 all over ebay.

But I got mine from Brit Parts for about £5 for 12.

Of course you don't have to Stop there you can replace the Filters or go as Far as you like.

Or you can even pay £250 to have a professional firm clean them for you.

I was quite happy to do them myself, as I found it dead easy to do and my Car Starts on the Button with just one turn of the Key.

If I was doing the Job again, I would probably go for New ones like I believe Carl (Jig Jag) did, as he managed to find some at an unbeatable price.

It's your Car and your Choice Daim

I'm just describing how I did it on my own Car 'Cherry Blossom'



The Rig I made to Clean my Injectors, you only need very low pressure.
Note the 9v PP9 and the Spare Injector Electrical Plug to which I attached two croc clips, plus of course an Aerosol Can of Wynns Carburetter Cleaner.



Injector Seals to Seal the Injector into the Manifold which should Always be replaced with New ones (I just put an old one on the Top) just to show the difference but take the old one off and fit New before you put the Injector Back into the Manifold.



Showing the Old Injector Seal in the Manifold, take it out and fit New Ones.



Who said owning an XJS was Cheap!

These little Square Cut 'O' rings £24! for 12!

That's about the Same as I paid for 12 Spark Plugs!

I got 12 of these 'O' Rings for about £5 from Brit Parts.

It pays to Shop around for this sort of Stuff.



Six Injectors not working but now She's all back together and Starts on the Button, after I cleaned them with my Home made Rig.

 

Agreed, but too complicated I feel, even though inevitably so given the physical dimensions of the engine bay

Once the thermostats are open, and the cross pipe entry point each side is blocked off, I am not sure the cross pipe does have any flow under these circumstances. The return "question mark" pipe from the bottom of the header tank does though, as the spigot it is connected to on the crosspipe leads down straight to the pump inlet, without affecting the main crosspipe, as it has a separate internal smaller bore concentrically located pipe within the large crosspipe/water pump connection pipe.

If I am right above, then when the thermostats are open, the crosspipe is not seeing flow out of the filler spout top spigot to the banjo and radtop bleed system. So the radiator only sees engine coolant flow from the thermostats. This "flow stalling phenomenon you have identified, I have just realised, could be the reason why OEM diagrams show the one way valve in the feed to the banjo from the filler spout preventing flow into the radiator banjo. At the expense, of course of purging air from the filler spout.

True enough, but does this have a significant effect, given that the heater (except on full cold) is always heating its matrix?

Will you still have an unpurged air build up in the filler spout? Secondly, how effective will this "sucking" action to purge the radiator air be compared with the OEM venturi system's low pressure effect?
I am always fascinated by these aspects of our cars Warrjon, and look forward to hearing your results. Anything that works well and simplifies the system gets my vote.
Greg

 

Yep the x-pipe has no flow once the thermostats are open.

The spigot on the x-pipe and the pipe at the bottom of the header tank both are in suction by the pump. The idea is that air is purged from the top of the radiator by this suction. The system does not need to purge via the filler neck as well as the header tank.


The flow is not supposed to go from the filler spout to the radiator it is designed to flow the other way, thus purging air from the top of the rad. Once air is purged then coolant will flow from the top of the rad to the filler neck, and to the header tank


Thinking about this a little more I don't think the dual purge will cause an issue as they are both sucking at the same point. I think Jaguar over engineered the system as the dual purge is unnecessary.

I have attached a good article on cooling systems, it's aimed at racing but does touch on road cars.

 

On an XJS V12 with ABS everything seems to be in the way of fitting a new Header Tank in a much higher position, so it works in the same way as many other road Cars.

You have the Master Cylinder Actuator on one side and unlike on a Lucas Car the Brake Pump on the other instead of the Washer bottle, which can be moved to another location.

Does anyone have any ideas, where to site a New Header Tank higher up on an XJS with ABS.



Where to Site a New Header Tank?
The Teves Master Cylinder Actuator Takes up a lot of room in the Engine Bay.



Where to Site a New Header Tank?
On this side the Brake Pump is right in the way.
Not the same on a Lucas Car, where space can be made.

 

Another project for you in the quiet time when winter returns.

Not easy in any way you look at it.

Ditching the ABS is one way, but that would upset a few people.

 

That ABS pump can be moved around... Like into the front right wheel well... Longer cables and hoses/pipes and done.

Or you get yourself a smaller pot, like in an X308. They are small and can wedge in narrowly but it isn't original

 

Btw. Your ABS pump looks different to mine...

 

Hi Guys

Cheers!

But job No1 is to get 'Cherry Blossom' back on the road for this Summer.

Although I'll still keep looking for a Header Tank that I might still be able to shoe in somewhere.

Could I use a Nylon one, or would it be too Hot and start melting or something?

 

they must be as they are two ends of the same pipe.


I never realised that; because they are linked I always assumed the radtop system was to purge all connections to that system.

So the air purge from the filler neck is intended to go downwards, and the tiny amount of flow will find its way to the pump if I understand you correctly? This follows logically, but I doubt if the air will go down the wide spout about 10 inches? But further, why did Jaguar link this and the venturi system together via the radtop pipe? They appear to be arguing with each other.
I agree the venturi suction and the question mark pipe suction are doing the same job, but the spout air purge is in opposition to them, while being linked to them it would seem. So with a single source of "suck", the crosspipe spigot and no venturi, an equal "suck" will be acting on both ends of the radtop bleed pipe, without what might be termed the extra suck from the venturi system? What stops the going one way only via the filler spout? Or never going to the spout?

Thanks for explaining your thinking Warrjon, but still a few conundrums in my mind!
Greg

 

Daim

Have you got a Pic of your ABS Pump?

 

Well, at least the connection looks different:

 

Hi Daim

Cheers!

Thanks for Posting that Photo of your ABS Pump

But apart from some minor design Tweaks, it looks almost exactly the same as on my 'Marelli' Car.

Also To-day I picked up 100 piece S/H Socket Set for £30 Metric and AF, so seeing as you are the 'Man who can' when it comes to Spanners, I

could do with your opinion, as well as that of others, as to what you think.

As soon as I've got some Photos I will put them on here, hopefully within the next couple of hours.

 

The tank does not need to higher, only the filler cap. If you look at most new cars these days the header tank is low down in the front of the car, BUT the filler cap is on a long neck and is the highest point in the system.

On my car the filler cap on the header tank is only slightly lower than the x-over filler cap. I have a replacement stainless steel header tank, but you could make one out of aluminium.

My engine builder Norman told me I would need to upgrade the cooling system for 6.7L. So I have been researching cooling systems, mostly how they do it in endurance racing.

 

Hi Warrjon

That is Very Interesting!

Would you happen to have a Photo, so that I can get some ideas as to where it might go.

 

Stock position and just lengthen the neck, ie raise the cap. Then 1/2 to 3/4 fill the header tank.

One thing I am unsure of is if the pump will suck the x-pipe with filler and spigot caped off dry, it shouldn't unless the cap leaks. I will using the 6.0L x-pipe that does not have the filler cap.

Thought, you could plumb the spigot on the filler neck to the LH thermostat housing, which currently goes to the header tank. Plug the current banjo bolt and plumb the current bleeder on the top left of the rad to the header tank. This will neaten up the pipes on the front of the engine.

 

Hi Warrjon

Again an interesting idea!

Since the Weather is due to improve (so they say) I'm hoping to get the Covers off and will have another look.

 

Since I've never been Mechanically minded, I've never had a great Selection of Tools but all that was about to change on the day I got my XJS.

Because I found out the hard way that when this Car goes wrong, it is going to cost a Shed Load of Cash to have a Garage or Shop try and fix it for you.

One of the problems being that everyone you meet tends to think that you're as Rich as Croesus, because this is the kind of Car that seems to

have you smelling of 'Old Money' or maybe that should just be 'Stinking Rich'

So as soon as they see you coming in this, the price tends to go up a tad! and to make matters worse there are Garages/Shops who really hate

working on Jags and may have never ever got their hands on a V12 or even seen one.

Which basically means that your Car will be their learning curve, while at the same time charging you for the privilege.

So you either need to be very rich and take her to a Specialist or else bite the bullet and have a go at fixing her yourself.

And since I'm not made of Money, that's what I decided to do but the one thing I've been lacking is a proper Socket Set.

Until Today!

When I walked into a Charity Shop/Thrift Shop and happened to eyeball this metal box that on closer inspection turned out to be a 100 piece

Socket Set, bearing a Price Tag of £59-99.

At which point I did what I normally do and made them an offer of half of what they were asking, which was £30 Cash and a look that said 'Take it

or leave it' (Not really make that a big Smile!)

The Jaguar Gods were on my side and they decided to accept my offer and here it is and while I don't have any idea of what make they are, I

have to say they look Ok to me and are a 50/50 Mix of Metric and AF.

What do you think, are these the type of Sockets that I need for Working on my XJS as I wasn't sure that I'd ever need to use AF.

But for only £30 they did look a bit of a bargain.



My First Socket Set: 100 Pieces Metric and AF for £30.

 

The Oil Cooler Broke on my Red Car 'Cherry Blossom' within about 10 Minutes of Starting her up but luckily I noticed all the Oil pouring out and

managed to switch the engine off in time.

So knowing how impossible it is to undo The Oil Cooler Pipes, as with two dissimilar Metals they Corrode themselves together, as if they had

been Welded.

I just cut the Metal Pipes on each side of the Oil Cooler.

Not the First time this has happened, as the same thing happened on my Blue XJS and that time I spent a full Seven days trying to undo the Oil

Pipes from the Oil Cooler without any success.

As the Blue Car was in regular use, I had a New Set of Oil Pipes made up at a local Hydraulic Shop for just a few pounds, rather than pay a

fortune for a new Set of OEM.

At the end of the day Oil Pipes are just Oil Pipes, there is nothing special about the OEM ones (except the big difference in price)

Then I bought a New Oil Cooler, which as I remember was about £250 and put it on.

And I am planning to do the same with my Red Car but only after She's passed the MOT and I've had a few 'Shake down runs' to make sure that

She is OK before I go and splash the Cash, on a new Oil Cooler and some Shop made after market Oil Pipes.

In other words I'm planning to go with exactly the same Set up, as I used on my Blue Car.

So as a Temporary Measure, I fitted a Bridging Pipe, (Without an Oil Cooler) which I found had been fitted to my Parts Car.

Meaning the Previous Owner had done the same thing, although I don't think that he ever planned to put an Oil Cooler back.

It also works fine on my Red Car as a Temporary measure, except there is a Problem as the Bridging Pipe hangs down Too Low, thanks to the

previous owner using the heaviest duty pipe that he could get his hands on.

As a result it looks as if it was much too stiff to bend right round to connect the Two Pipes together as it was and so he overcame this by using a

drop down elbow.

And while this may have worked for him it doesn't work for me, as there are lots of Road Humps in my Road that it might catch on.

So what I am planning to do is have another Bridging Pipe made up, out of a less heavy duty pipe that can bend round in a curve without having

to use the drop down elbow.

Which will then give me enough ground clearance.

The only concern that I have, is what could possibly happen if the hot oil going through it caused the Pipe to Kink, so that Oil was unable to flow

through it.

Would it Blow the Engine if that happened?



Temporary Bridging Pipe, as used by the PO on his own Car but on my Car (Pictured) the drop down elbow makes it hang Too Low.
So I'm planning to have another one made from a less heavy duty material.
But would it Blow the Engine, if that Pipe got a Kink, that either restricted or cut off the Oil Flow through this Bridging Pipe?

 

First of all: congrats on your new socket set! You'll notice though, that a socket set is never with all the tools you need... You'll be buying more soon

Secondly: £30 seems quite steap. You can get some sets with 160 pieces and more for about €50 - brand new and made in Germany (like from Mannesmann, my first large tool kit). As long as you are happy, all is okay

Thirdly: you'll be looking for more tools yet I've got a huge, long Amazon wishlist with tools I randomly purchase if I have a few € left over at the end of the month... Next set to buy: tools to take the Delco A6 air con compressor apart... Around €55 for a kit which would work with all common compressors... Helps as all our vehicles have compressors and my dad is the same type of person: better to overhaul and try than it is to simply buy new.

Last and fourthly: New tools = new tasks! New front crankshaft seal, new this, new that, banana here, oranges there