I have an interesting leak situation with my 2005 Super V8 with 191k miles. I parked it with only a symptom of smelling coolant through the HVAC after turns or acceleration (independent of heater running). Sounds like valley stuff right? Well the system held pressure pretty great right up to the 120 kilopascals listed on the cap so I just set to looking everywhere.
No drip off the back of the engine/transmission. Discovered a long term leak from the water pump/engine block gasket. So I decided to swap the serpentine belt and that gasket. I also discovered the thermostat bypass to engine block hose was super swelled to the point of surrounding a metal edge of the block. So I tried to find that too.
Swapped it. The new gasket was the 1.5mm thick from Mahle, far thicker than what I now know is the original 0.4mm thick metal gasket. Put coolant back in like a dummy and didn't even get to fill it up before the water pump gasket was leaking fairly profusely and coolant was running down the back of the engine too!
I got the gasket warranty-swapped and the bypass hose installed (it was a locally available very close to spec hose, again like a dummy). Put the new water pump gasket in and... it can almost hold the weight of the water in the system I think. But with the slightest pressure applied water streams out the top of the gasket, coincidentally aimed right at the bypass hose. So water runs down the front of the engine and the back of the engine.
The bypass hose does not appear to be leaking, though it seems from pictures of the supercharger removal job that if the bypass hose leaked at the engine block point, the water would go the same way as the valley hose. Well, the water pump could also potentially drain down the valley as well.
The substance draining down the back of the engine runs down both sides of the transmission. On the right (true right) side is a coolant mixture. On the left side is practically pure water (in accordance with what I have been adding, I don't want to use coolant until I know I got the leaks). What is streaming from the water pump is also pure water.
So, should I just fix the water pump gasket for now? Should I go ahead and order the valley hose job parts? I'm broke and this is my daily driver, like a dummy hahaha!

 

Just how long have you owned this Jaguar?

 

Almost a year. It's my second X350. My first is an 06 XJR 130k miles that I use as a parts car since it got totaled. I had it for about a year as well before it was taken from me
Why do you ask?

 

Having had it that long, smelling coolant, without investigating is why i asked.

These cars are often dumped, way past their ready to be serviced time.

Anything i ever bought used, is in need of repair, thats why the last owner sold or traded it.

 

I think I must have misstated something. It just started the symptom of coolant smell through the HVAC about 3 days before I got it on jack stands. I took my time with diagnosis and kept a keen eye on coolant level and temps from obd2. I've been working on cars for 17 years and am the liaison my friends bring to go buy cars. I understand used cars needs and specialize in diagnosis.
Besides, according to what I've read and experienced with these Jags, if you don't smell coolant at least a little, you might not have any haha!

 

Could be i misunderstood.
Any smell of coolant at all, means there is an issue, & it gets my attention right now.
Many others not so much, just add coolant & watch to see if it gets worse.

 

rufeo690;

Not sure this will be helpful but I'm attaching a photograph of the valley hose(s) running under the supercharger of an 07' SV8. My hope is this will give you a visual for what you're dealing with. There are three hoses: One running to the ERG (lower hose in the photo), one returning back from the throttle body towards the water pump - the infamous valley hose - the reduction I circled is the frequent point of rupture. And a "U" shaped hose on the right. I do not recall what this later hose is for.
The first two hoses mentioned are on the same circuit, supply and return, so unfortunately you cannot just pinch off the accessible supply side hose to verify if this stops the leak. Of coarse you have to pull the supercharge to get this level of access.

Best Regards, William

 

Wow that's clean! Did you add that bit of material?
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clubairth1;

You're seeing this area upon reassembly, everything has been cleaned up. I was replacing valley hoses and other bits that had warn, or are difficult to replace (knock sensors). The material is heat shielding, metalized on one side. My thought process is there was insulation over these hoses helping keep the SC cooler. Thus the hoses were exposed to the temps over the engine. This thermal layer I have added hopefully reduces the heat stress to the hoses, and the thin woven material hopefully reduces wear due to abrasion/vibration against the top of the engine. I believe I read the heat shielding suggestion in a valley hose post by another forum member.

Best Regards, William

 

Since we have a group of experienced water problem folks assembled here, I'd submit my symptoms and ask for a diagnosis. AC or heat on it smells of antifreeze, if the HVAC is turned off by clicking the off icon in the GPS screen, no odor at all. I have pulled the pump fuse (54 I think) can't say it made that much difference. I put approved dye in the coolant, no sign of it under hood under car or on the floor mats. My next step was to pull the glove box ETC. to get a look at the heater core and under dash hoses, but if that is a waste of time I would really love a push in the right direction. I've put about a quart of antifreeze in it since bought it a few months back.

 

Eric-in-Texas;

I do not have experience with heater core problems but do have an experience with the flexible hose union, on the engine side of the firewall, where the aluminum heater tubes running along the passenger side fenders turn up and snake their way through the firewall to the heater core. There is a short run of hose coupling the heater tubes (mentioned above), and the metal fittings that pass through the firewall. To access this the fresh air intake box needs to be removed (as if you were trying to access the ECM).

My symptoms were a slow dripping coolant leak down the passenger side of my transmission, but only when the engine was really hot. I never got coolant inside the car. I can't say I ever noticed the smell of coolant. My issue also occurred independent of HVAC on/off. You show to have an XJR so your specific coupler is straight through (possibly pn C2C1980). I have mid-cabin HVAC so my coupler "Y's" off. The point is I was weeping coolant out one of the hose to metal tube unions. Replaced it and problem fixed.

Your symptoms are different but before jumping in to replace your heater core (assuming you don't have coolant inside the car) might want to eliminate easier/less expensive possibilities.
Let us know what you conclude.... learning opportunity for us all.

Best Regards, William

 

If your adding coolant then I would do a pressure test when the engine is cold. Have you done any repairs on the engine where coolant lines were removed?
I ask because any spilled coolant on the engine can leave lingering smells for quite a long time afterwards. Be aware that you smell could be coming in thru the cabin filter too. Have you serviced or inspected that?
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I haven't released any coolant doing any repairs, I did replace the cabin filter. The fact that the cabin filter draws air from where it does, nags at me. I can see how that could be the source of the problem. However, I've never smelled coolant in the engine bay, & the UV light picks up nothing & the coolant is fairly luminescent, if you shine it into the filler tube. I'm nearly to the point of keeping it close to home for fear that it could really let go, and have to be flat-bedded home.

 

If you pressure test the system cold and it is the heater core (which is very rare thankfully!). I know you said it has been tested and held pressure but then you did some additional repairs.
You should get coolant to come out on the ground from the condensate drain.

Can you get your UV light around in the area? It's not exposed so the condensate runs around on the bottom of the car a bit before falling off.
This might not be easy without getting the car in the air. But possible on jack stands.

Hope it's not too cold where your working??
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I have a 4 post lift, in a shop with a wood stove, so working conditions aren't an issue, (unless you count my being a bit of a messy Marvin ). That said, nothing shows any trace of leaking, top or bottom, Though I can't see well under the supercharger, it still should show some trace of dye somewhere if the leak was under hood or under chassis. When I put A/C dye in 1997 xj6, you could see it from across the room. i don't know that this is similar, but I was hoping. Whatever it takes is the attitude, but throwing parts at it without knowing isn't really a good strategy IMO
My oldest son has volunteered to pull the glove-box ETC, to do the exploratory under dash, hopefully it will reveal a bad hose or o-ring, or even a heater core, and I can get back to enjoying the car. Down side of that is; he is fairly busy, and it will have to be at his convenience.
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