Gentle listers, I have a 2004 VDP which, has given me yeoman service as yet save the fact that I changed out the air suspension for the Arnot shocks. However, now I have a mysterious leak. There is never a puddle or any smell. There is only the daily use every three or four-day light illumination. The refill is only about a cup or less each time and I use 50/50 orange stuff.

In searching the archives, I find a bunch of suggestions for supercharged Jags, but really none for regularly aspirated ones. I have taken off the fill tank and didn't see anything amiss there including the small top return hose/area. Similarly, I didn't see anything amiss with the various hoses I could access after that was removed. Nor was there any wetness under the water pump area. Boy, that's a snakes nest of really stupidly put together (clamped rings) hoses and "Y"s - anything for ease of manufacture, but NOT of repair. In any case, I have to ask if there are any pattern failure points on this system identified by now. The car has about 70K on it, but that means nothing where plastic and unreinforced hoses are concerned.

Any suggestions? I'm a bit loathe to tear the front apart any more than I have to since it's so complicated. I will, of course, if I have to. The weather could be better for rummaging around in the viscera though.

TIA. Beast regards, Brian

 

Wow, sorry you have mentioned everything I may of said check. If you have no evidence of a leak with actual water to see it may be being held up by the under Tray but I doubt it but worth may be removing the tray run the car and see if anything drips down. Other an that the water is burning off but if that was the case you would smell it. Sorry this is not more helpful but the water is going somewhere. It would show in the water if there was a head gasket problem so how about exhaust? How's the car driving? My old Range Rover used to use water because of porous cylinder liners but I have not heard of this with Jags. Keep us informed please.

 

Hi, thanks for commenting. The car runs fine. There is no evidence of any oil in the water or vice versa - oil not milky. No evidence of bubbles in the water while running so I have to assume the head gasket is OK plus the car has never been overheated. I will get into this deeper when better weather permits. I did Dremel the rings off two of the hoses (cut them nearly in two then twisted/manipulated them off the rest of the way), but I didn't slice into the hoses AFAIK. Used worm clamps on them so it'll be a bit easier taking things off in the future. The car leaks the same after I explored as before so I don't think it's anything I touched.

I was hoping to hear of any pattern failures that have presented themselves by now like the dodgy hose under the supercharger on these cars so equipped. Cars this old usually do present their flaws for all to view and catalogues of those flaws are the best places to start when troubleshooting. Jaguar sure did some things weirdly like the oil filler screw-on cap being collared so the whole 'beauty' engine cover has to come off with it. Makes it hard to remove the cover and keep the cap on while running to look for drips, seeps, and spurts. I guess I'll finally have to divest it of its collar a bit, as I've been planning to do, so I can run the car with the cover off and solve that pesky nitnoy.

I;m sure I'll find even more annoying things as I get deeper into the abyss.

Brian

 

The connectors from the heater hoses (both the return and feed) that are just behind the last cylinders on each bank tend to drip right onto the exhaust, leaving hardly a trail of evidence that it was there. Look for an orange film. I've changed that octopus of heater hose once already from these points of connection, and recently just cut the dang thing off the replacement when it started leaking again on the driver side (inserted a 3/4 x 3/4 x 3/8 tee instead)

 

Hi H2oboy for the info. I'll check it out when next the days allow and SWMBOs "Honey Dos" are at low ebb.

Best, Brian

 

Well, today it got warm enough to do some skulking around in the car and I particularly looked at the area H20Boy mentioned only to find it completely dry (passenger side as I saw no hose connections on the driver's side - was that an oversight?). I had the engine running so any streams, spurts, dribbles or drops might be more readily noticed. Nothing. All is dry. Mysterious loss still evidenced by low filler tank and telltale dash admonition. Next, jack car up, install stand and clamber under car, remove under tray, start car and try to see anything amiss.

I did discover one thing though. Those of you who have read my post must have wondered what I was talking about with the oil filler "collar." Until just now, every time I went to unscrew the oil filler cap the entire stalk (w/collar) came with it. I didn't know till just now the filler cap came apart from the stalk/pipe/stand. Of course it makes sense, but so many other things don't. Now the cap, though difficult to unscrew, came apart as it was supposed to. I suppose the heated engine expansion differential married the stalk to the valve cover more than the plastic top cap to the plastic stalk.

Mea culpa, mea maxima culpa.

So, that was nice. Hell, I've had this car for years now and it's never come apart as it was supposed to. Who tells you these things?

Anyway, no joy on the mysterious leak. Still a mystery. Any more ideas?

 

Hello and welcome SUSU, just wanted to leave some input from experience.I have seen x350 V8 NA leak from behind the waterpump,just as a slight weeping leak that doesnt puddle,nor cause a immediate MIL.
Also I have seen them leak just very slightly at the inlet pipe under the throttle body.Also I have seen them leak at the bleed screw at the expansion tank and even at the seem of the tank at miles as low as 58k.ALL of these leaks started out as a weeping leaks and usually progressed into a major leaks.My advice is to pressurize the sytem with a manual pressurizer,by screwing the device onto the expansion tank,pump 15-18psi into it and listen.I can assure you that you can fix this and locate the gremlin,by being proactive.You can fix this,and worst case of a leak was a vanden plas with electrolosis at the waterpump.The electrical current was causing the coolant molecules to change into a paste like substance looking like candle wax..it was at such a slow rate that it was hard to catch.But once the undercover or batwing was removed that little bugger revealed itself.I am so convinced that you can identify the culprit,that I am willing to quit my job and start selling bottled water...lol...until next time Happy Wrenching!

 

Its common on these cars to have a slow leak at the coolant tank bleed nipple. Most of these tanks last about 60K. It can be hard to see, but pressure testing will show it up.

 

I had a very similar problem on my '04 VDP when I purchased it about 6 months ago. I did have a very faint coolant smell, occasionally a dime sized (15mm?) spot on the floor under the car. Could not find any seepage but saw a very faint stain under the water pump that was not fresh. I decided to replace the water pump, and purchased an after market pump. When I got the pump off the car, I saw nothing wrong with it, and it was a better quality pump than the new one I bought, so I reinstalled it with a new metal gasket and a very light smear of silicone sealer. No problem since, so I assume it was a leaking gasket.

 

OK. Thanks again for more info - all good. I will address each of these as I am able.

Best, Brian

 

OK, here's what's transpired so far. I've had the car on ramps overnight and took off all the undertrays. This morning I got a coolant pressure adapted (at O'Reilleys - fit my X350, but not the X308) and pressurized the system to 16 lbs. It did start a slow leak which manifest itself under the car below the transmission. The bolts are wet and so is another nearby line. The pressure was slowly going down and while it was, I used a trouble light to try and see the culprit. NO GO. There is nothing visibly dripping or weeping from under the car. Up top, I looked at what I could using a mirror, but the area is so crowded I could see nothing at all wet or where it might be coming from. I used my hand to feel around up from the bottom and down from behind the engine, but all proved naught. I decided to see if I could get a comprehensive picture of the cooling system routing or schematic. Alas, I found nothing but parts pictures without any but a rudimentary description of where they are. I have an introductory Technical Guide for the X308 and it has a cooling schematic in it, but we know that is all different for the X350. I have never even heard of a Technical Guide for the X350, so that's "come a cropper".

Again, I implore you gurus to see if you can tell me what of where the leak might be coming from. I understand that, because the front is up on ramps, the leak could be coming from up front and flowing back so I'll check more thoroughly up front again. I will google X350 Technical Guide, but I have slim to no hope I'll hit pay dirt. In the meantime I want to send this off in hopes of an answer

On the plus side, I changed the oil and filter and inspected all the bushings and, in general, found everything ship shape. Best, Brian

 

Wow! you are really going after that leak!

If you are not careful you are going to find it!

Seriously, I am not familiar with the 4.2 engine but I have read that they

are prone to leak into the vee of the engine.

Ignore me if you have looked and are past that stage.

 

I spoke to my Jag Mechanic good old Ron at Leith Jaguar in Cary NC and he said he would look at the heating circulatory pump that is fitted to the X350 they are prone to leaking but are very hard to see actually leaking if that makes any sense. This might be something to look at but apparently they are really hard to get at.

 

This pump is directly under the coolant header tank. I have never heard of one leaking, but a loose hose can leak anywhere.

 

Someone will tell you were you can get them for free but I used

Jaguar X350 XJ8 XJR Technical Documentation for Download

Only a few pounds......

Now if there was anyway I could send you the files I would, so someone tell me please as they are to large to email!

 

No need Peter the recipients just download it themselves.

 

Hi, and thanks, Peter, for that URL. I just went ahead and popped for the X350 2004 Technical Guide. It helps a bit, but isn't really what I was hoping for. I was hoping to see some kind of drawing depicting the actual routing of the water hoses in general similar to that of the engine management components locations or even the AC components locations. I was hoping to get the whole engine pictured with the hoses in black outlines and the rest of the surrounding stuff grayed or ghosted-in so the routs of each hose could, in fact be determined. That way, I'd ascertain whether or not there is some kind of hose going under or around the intake plenum and exiting the rear of the engine (there seems to be in the drawing of the transmission oil cooler pipes). If there isn't then all the hoses and leaks would be confined to the front and that cuts down the search. As it is, I have this leak that only manifests itself at the rear of the engine dripping down from the transmission.

I have the JTIS covering this car and I've downloaded the workshop manual kindly provided by this forum. Amazingly, I have not found any reference in the JTIS #21 for the cooling system under any of the areas. This whole thing is most perplexing and downright dumb. Jaguar must have known that the various hoses would perish at some time, perhaps even under warranty when they still pretend to care. It seems like they would have provided some way to suss out insidious leaks without tearing the whole car apart.
A little too cold to go rummaging around out there today.

Best, brian

 

"I have this leak that only manifests itself at the rear of the engine dripping down from the transmission."

 

"After much rummaging and crawling around under the car the leak was passenger side dripping from gearbox bell housing. Figured it was heater plumbing related, no. It was apparently coming from the back of the "vee".

This was an S type but 4.2 v8 N/A engine.

https://www.jaguarforums.com/forum/s...-engine-72354/

 

I wonder how similar the X350 layout is to the 4.2 X150 XK? (see attached)