After changing or repairing all three coolant pumps and the thermostat I had 3600 care free miles before it began losing coolant again. It was blowing coolant at the pressure cap so I replaced it and no more blow by, but it still had a serious coolant loss.

I had put the front on ramps and today I let it warm up on the ramps while I checked for codes (nothing unusual) and Looking underneath with the engine still running there was a coolant drip under the right side from a hose just above where the brake lines are held onto the right side rail and above the pulley of the alternator; the drip appeared just forward of the spring clamp and the bottom of the hose appeared to be wet so I apparently need to replace the hose. (thank goodness it is not the valley hose....yet)


Anyone know off the top of your head the part number for this hose? Any suggestions for getting to it from below or above? And whether I need to drain all the coolant before digging in and if so what is the best way to drain it?


Photos show the hose in question in the center (the one without a part number), one with flash and one with black light showing the drip as white.

 

My hose set up in that area is different from yours so I cannot help you Phil.

I replaced all the hoses about a year ago.

I am surprised no one else can help.

John

 

Thanks for the reply, John. The JEPC doesn't show any hose like this one nor does the X350 workshop manual anywhere that I can find. I tried the Jaguarmerriamparts cooling system diagrams and I don't see one with a quick connect end on it or recognize a shape like this one there either.

Guess I'll have to bite the bullet and drain the system and see if I can get it off to look for a part number. I'd like to use our British car club's lift but it will probably have to sit for a while to find another hose, so I'll have to do it on my back in the car port. I just hope I can reach up high enough from the bottom to disconnect it because I can't even see it from the top (which is why I had not found it before).

Man there are a lot of hoses on this car!

 

I think my coolant leak is in the lower heater hose and I found a couple of threads, one of which was on a non- super charged car but listed a hose for the SC version he received first.

"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.

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.


I need to correct my previous post--the hose in the photo and the part number are for a S/C 4.2 that I got from my dealer. The correct hose for the N/A 4.2L non SC is part AJ811763."


Can anyone confirm the part number of the lower heater hose on a 2006 supercharged car? AJ89746? The photo is from that thread and is supposed to be that hose.


Also, how does the quick connect come off? i see a blue plastic band on the top one; does it just pry up? Thanks for any advice.

 

I'm afraid to mention it but........ Bars Leaks

 

Phil have a look at : https://www.eeuroparts.com/Parts/353...-Hose-AJ89746/

 

I gave in and started removing stuff like the coolant tank and top radiator hose and discovered my top radiator hose has a T with a short hose to the lower heater pipe, nothing like these other hoses or the top rad hose in the EPC. I emailed Merriam to ask if the part number C2C32836 they list for the top rad hose of a supercharged V8 has the T because their diagram does not.

Another case of Murphy's Law, "The repairman will never have seen a model quite like yours." At least I can see the lower hose from the top now but reaching it is another question. I am working on the top hose quick connect in another thread and so far no joy in getting it off to get to the bottom one. Trying to not break anything and 11 year old plastic next to a heat source tends to do just that.

Oh yes. Bars Leaks. I know Jaguar actually recommended it in the early days, but stopped when so many series IIIs ended up plugged with radiator sludge. I've used the aluminum dust stop leak in our old minivans with good results, but I think it is a last resort for the virgin SV8. Still if I get this heater hose replaced and it still leaks..... The strange thing is that I did a pressure test at the coolant tank not long ago and it held 16 PSI for hours, but definitely had a serious leak at or above the lower heater hose now.

 

Got good news from jaguarmerriamparts today when Tom checked the stock and said their upper radiator hose C2C32836 does have the T and the heater hose and it comes with the quick connector on the heater hose. Great. and all for $22.61. I asked about the straight quick connector on the upper heater hose and Tom said they were not available separately but should come with whatever hose assembly goes to that upper pipe. I found C2C24691 in the HVAC section and called back but they did not have that one close at hand but the fellow who answered that time said it should come with the quick connector also so I ordered them both and for $56.33 I hope to be back in business with new heater hoses and connectors all around.

My local guys at Ozark Import Specialists said the radiator hose was not available to them as their supplied didn't stock it, so a big thanks to merriam for stocking these at a reasonable price.

 

As a followup I found these color diagrams referred to in another thread as V8 cooling diagrams for (I think) an XK, but they seem pretty accurate for some parts of my Super V8 cooling and HVAC systems - more accurate than the line drawings in the EPC or the repair manual - although missing the supercharger cooling. These are screen shots from a pdf file and a copy of the pdf file they came from.

 

Followup to this post:

The hoses arrived yesterday and the C2C32836 top radiator hose was absolutely great and included the heater pipe quick connector on the smaller hose, two new spring clamps on the larger hoses, and even a plastic holder on the engine side hose spring clamp to hold it open until it is installed.

The C2C24691 coolant hose, however, was not at all like the hoses on my car so I had to re-install the straight quick connector for the upper heater pipe on my old hose(s) and use them again. This hose is part of an “octopus” hose that connects the upper heater pipe via the straight quick connect, the auxiliary coolant pump below the overflow tank via a short vertical hose and spring clamp, the supercharger radiator via a hose that goes beside the right side of main radiator and around a 90 degree bend to the super charger radiator in front of the main radiator via a brown plastic quick connect with a wire keeper, and the overflow tank via a larger right angle brown plastic quick connect with a wire keeper.


I looked at Merriam's diagrams again and think the Octopus hose may be C2C28125 - "Upr return hose" on one of the cooling system diagrams (#9 on the diagram below) rather than the HVAC diagram I looked at to find the hose from the Auxiliary coolant pump. The main catalog shows this to be N/A, but if you click on it you get a page that says it is $94.56. Fortunately I didn't have any leaks after I got the new upper radiator hose installed and the old hoses and expansion tank reconnected...at least not yet.