Howdy folks,
I have been working the new job and I'm glad to have it, but it's taken more time away than I thought and have less online time. Here's my quandary.... I'm hoping for ideas, thoughts, tests, etc.... Please and thank you!

05 XJR with 115k miles on her. I have developed a coolant leak over the last week+ and it's VERY intermittent at best. I was able to reproduce it once in the driveway over the weekend over HOURS or trying to reproduce it and all I can see is the coolant is being showered over the inside of the engine bay (and hot parts that make smoke) by the SC belt. This morning, after my regular 30 min commute to work, it didn't smoke, etc. Went out about lunchtime and there was A LOT of coolant on the ground.

This weekend, I had it running at idle for an hour, did some stop and go, did some driving at speed, etc. The only time it did it at home was the first day, after about 15-20 mins at idle and I heard an audible click and then it started coming off of the SC belt. I could not see where it was coming from underneath. Day two, I removed ALLL the cover from the bottom and top to try to see it when it happened again. But, HOURS of running, and no sign of it... Figures!

I thought that if it was the T-Stat or the water pump/seal, then sitting at idle in 90 deg temps for an hour+, along with all the other tests, would surely be enough to get it flowing through them and if they were the culprit, I'd imagine it'd have leaked then. Nope. Thanks!!!

R,
Rags

 

Hey Rags. I had a spill and it isn't intermittent. Posted my issue with pics. I think I fixed mine but still hoping someone tells me the other hose number.

So nothing visual for you? In and around the reservoir is the obvious first place to look. I would remove the Reservoir inlet hose and inspect the nipple.

2nd, I'd recommend doing a pressure test. Add some dye. Most auto stores lend out pressure testers here in Minnesota (Auto Zone, O'Reilly, etc)and you can drive from store to store to find one with a cap that fits the reservoir.

Or try this (I don't know if it comes with a cap the will fit our cars though):
Sears.com

Intermittent? Does it get to normal operating temp? If yes, then check the flow diagram as well for something that flows once the thermostat is opened.

 

First off let me say I have the V6 so am not fully up-to-speed on the V8s, but for both engines there is a common fault area for leaks. There is a vent pipe connecting at top rear of the header tank and the moulded nipple the pipe connects onto fractures over time letting out coolant, and as this is right at the top of the coolant circuit, any coolant coming out of here will go all over the place. I believe the thermostat housing made of plastic can also crack and spray coolant everywhere. Apart from that, if the seal on the water pump fails, clearly this can also spray coolant out. Look around the engine compartment in the dark with a torch to see glint of coolant drops. In the day these are difficult to see as the eye adjusts to daylight.

 

Check the hose that goes from the water rail to the block
Mine developed a pinhole leak and needed replacing (long job)

Also the right angle bend on the 1in hose that comes of the front of the water rail (radiator side). I have had this go 3 times at the right angle bend. The last time I replaced it I cut the bend out of the new hose and added a plastic 90deg bend. Problem has never occurred again

Cheers
34by151

 

Hi Rags,

Our XJR developed a pinhole leak in one of the hoses in the rats nest just below the coolant reservoir. In order to see it, I had to raise the car on ramps and inspect from below using a flashlight/torch. The pinhole was squirting a very thin stream onto the bottom of the reservoir. I replaced the leaking hose and all the other engine coolant hoses in that area. I saved the supercharger hoses for later. The supercharger coolant pump is also in that vicinity. I haven't studied its operation to know whether it runs constantly or intermittently, but if it runs intermittently, perhaps you have a leak in a hose at the pump output and that is why your leak isn't constant? I also haven't studied whether the supercharger coolant and engine coolant are co-mingled - if they're separate, then forget I said anything!

Please keep us informed.

Cheers,

Don

 

I think you're getting a lot of great ideas on where to look Ragman. That said, I caught my leak virtually when it happened. Still, Dexcool was in a lot of places. It doesn't clean up easy and if your engine bay is covered, try the dye and pressure test.

 

Thought this might help you also Ragman. I'm attaching a coolant flow diagram for your troubleshooting. The intermittent leads me to suspect that is could be happening after the thermostat kicks in.

FYI for those of you who might view this in the future and may not know, flow diagrams don't necessarily correctly position components in the diagram. The documents purpose is to show the flow, not part location.

 

Hola Mi Amigos!
I left Friday about 3PM EDT and then got home late Sun night. I had it up on ramps with ALL the cover (top and bottom) and It would NOT leak... GRRR... Rain after than and then I was gone. I'm hoping to get to Anya soooon and try to figure out the issue(s). I would assume that if it were the T-stat, then it'd do it again after idling for an hour or after cooling down and then doing the idle test again w/o a leak. MONSTEROUSLY aggravated and hoping to get a determination of this as well.

Live mentioned, I was thinking a SC return that's buried from a gut feeling...It's not coming from the reservoir, it's nipples or hoses on top as they're dry and it's coming from the from under it somewhere that is only needed "on demand" it'd seem. The SC return line is my Guess at the moment.

I did use the storm clouds and my 620 lumen torch (from my M4 Carbine) to search the engine bay and it's all over. The day after the first instance, I used the GUNK engine cleaner after it cooled. I didn't do the entire bay, but focused on the affected area.

I needed coolant and water at the time to get home, so I used what I had. full strength (green) coolant and mixed with water. It got worse. I have my ramps out and ready so I can drive it and await it to happen and then just pull up on them with my tools handy. I removed the air hose, for a better view, and it wouldn't stay running. I tried to trick it into thinking it was connected to no avail. I'm going to try as soon as I can. I rode the Harley today and with thunder storms tomorrow, I'll be in the Durango.

I am REALLY hoping to get it to leak after work today and then get her on the ramps (extra goggles this time). Thanks folks. As I still don't know what it is, if anyone has more ideas, please drop em in!!! Thank you again!!!!!

R,
Rags

 

FOUND IT!!! It's a hose in front of the rest coming off the lower aluminum split from the block. Right at the clamp level. Now, let the engine cool... (90+° all week) and then tear it down. Harley & Durango will get some extra ATTN this week... Thanks y'all!!!

R,
Rags

 

Sounds like the one I modified on my XJR after replacing it for the 3rd time

If it is the one that has the 90 deg bend right near the clamp its the same one.
I cur out the 90deg bend on the 3rd new hose and added a plastic bend, problem has never recurred

Cheers
34by151

 

PICS please sir

 

Sean,

Thank you for posting the coolant flow diagram! Very helpful!

At first glance, it does seem to confirm that the engine coolant and supercharger coolant do communicate, at the very least via the thin hose from the reservoir to the supercharger cooler. The diagram makes it appear that the water pump's outputs connect to the charge coolers, but I'm assuming they actually connect to the open hose ends shown in the upper and lower left corners of the rectangle that encompasses components 1,3, 4, 5, 6, and 7. Can you clarify?

Thanks,

Don

 

The open ends at the water pump (marked 5) is meant to represent the coolant flow though the block. The other open ends (top and bottom left of the bock) represent where it come back out of the bock.

The small hose connecting the S/C coolant with the engine coolant is only for expansion. Its not actually pumped by the water pump, aux pump or s/c pump.

In other words the S/C circuit shares the reservoir with the engine coolant

Cheers
34by151

 

Yes it is a nest under the header tank you would have thought they could have put a bit more of thought into the route of all those pipes just changed the supercharger hoses on mine and you have to remove the bumper to get to the hoses as the supercharger cooler pump is down behind it I think the other pump below the header tank is for the heater in the car

 

Agreed. It would have been beneficial to show a dotted line across the SC's (4&6) for clarity and then show those flows out of the block as solid lines.

Interesting that the SC is un-impacted by the thermostat. I hadn't thought that through before posting (and looking) at the diagram.

The down side of flow diagrams I guess.

 

It took a bit to get some of the actual affected line and then a diagram of the lines so I can show which one is spraying... Here they are...

 

Thanks man. Sorry, my request was more work than I was thinking. I'm curious. Does anyone know if there is a coolant replacement hose kit for all of these shown in the diagram?

 

well, as I phoned the Jaguar dealership and tried to explain to them the hose that I needed and really confused him quite a bit, I decided I would try some good old fashioned guessing!

So, as the leak was right at the bottom of the clamp I thought that I would just cut off that part of the hose as it was over a foot long and then put it back on the manifold and clamp it back together. After removing the reservoir and losing all of the coolant there into the large pan I put underneath the car, I was able to get to the hose and cut off the offending part, put it back on and then put everything back together.

I went for a joyride and got the supercharger going and around a hundred and ten miles per hour and got it nice and warm and came home and grabbed it and no leak! So, here are some pictures of the place that it was leaking from. You will be able to pick out right away which end the leak was at.

Ethel and Ruth did me well while Anya took a break.

 

Not the same one as I had trouble with.
You will normally get issues right near a bend or near the fitting as you have discovered.

Now you have it working again I would plan to replace the hose as it is likely to go in another spot on the same hose.
Also check the rest for signs of being soft near the ends and bends and plan to repace those as well.
You are always better off getting a spare set of hoses now rather tan waiting for an issue and then trying to get them in a hurry




You can often get what you need from the local autoparts store as you will find some on the shelf can be cut down to fit

Cheers
34by151

 

Thanks! I absolutely agree. Now that I can actually take it to a shop and get a part #. All the other molded hoses seemed sound and not squishy like I'd imagine they would be. Disconnecting the resivor was the hardest part and it was a good thing I had a pan under the car. It was coming out of everywhere. lol 90+° all week and Ethel chose this week to stop pumping out cold air so Ruth was my girl! Thank you again y'all!!

R,
Rags


One addition I'd like to make is that the hose, from the alum manifold, runs down to the windscreen washer reservoir and looks like it has a plastic connection to a metal pipe. I had to unclamp the connection to the reservoir tank and it looks like there is something similar for this. My initial thought, as this appears to be "good" all other places, I want to get the replacement hose and then a "coupling kit" to add the 3cm back in that I removed. It's a work in progress, but it was found and, for now, not leaking. Thanks again to all of you. I hope that work will calm down a bit (fat chance) soon and I can enjoy more time on here!!