Finally discovered why my coolant level keeps dropping and signals the fault message. Put her up on the quickjack and crawled under with the work light. Took some time but I found a drip under the top hose. Dug in a little deeper and noticed a wet spot on the plastic end just above the outlet. Appears to be a microscopic crack as I can dry it with a paper towel and it reappears in a few seconds. The leak is so slow that it drips down onto the bottom of the radiator and is absorbed by the foam seal ! When I decided a new radiator was the cure, I began the disassembly starting with the chin on the bottom and as soon as I removed the first screw a trickle of coolant dribbled out. Apparently this orange coolant will evaporate from the foam when the car is not being driven and that is why I never saw a spot under the front of the car. So I ordered a replacement radiator from the autoparts store. When it arrived I remove the old one and compared it to the new one and found that the recepticles for the transmission cooler were not correct. The fittings were threaded inside and out and had no place for the o- ring. Any one here have any experience
with the all alloy ones from China? I normally try to avoid dealing with that origin especially on a big ticket item.

 

To my knowledge, the radiator transmission fittings changed with the transmission change (5sp to 6sp, unsure about the XKR). A long time ago, someone posted a part# for a gender changer of sort (a brass plumbing part), but you are probably better off returning this radiator for the correct part.

Best of luck, keep us posted

 

No experience with the chinesium radiators, but Radtec in the UK does have an alloy radiator available. It does cost a pretty penny tho.

https://radtec.co.uk/shop/makes/jagu...xk/jaguar-xkr/

 

https://www.jaguarforums.com/forum/x...cement-282153/

 

I wish a better alternative radiator for the XK was widely available vs the one you can get from Nissens. It’s funny, I just looked on rockauto and they only show a side view of it. 😂 The reason is that the core is the old school tube and fin design vs the higher efficiency of the bar and plate design of the oem radiator. So what’s the big deal? They run 5*-10* hotter due to the less efficient core. That UK radiator place was $1038 shipped. Pretty steep.

The place below has replicated a radiator and a intercooler radiator for us before on an Aston Martin and they do beautiful work. Even though they don’t list ones for the XK8, the link should give you an idea what they would charge for an XK8. You have to ship your radiator to them and they’ll custom build you one even with the internal transmission oil cooler.

https://wizardcooling.com/series-416...!make%3DJAGUAR

I know this isn’t most people’s cup of tea to get a custom radiator but, I’m merely suggesting this as a possibility for anyone that’s unhappy with the only alternative aftermarket radiator.

 

Not much of a savings compared to the UK place considering the price of that XJS radiator being up to $809 and you have to ship your current radiator (I assume you pay for the shipping of your radiator to them as well?)


Given that they’re both aluminum radiators, it would really depend on how much they charge for that custom radiator plus the shipping.

 

A while back, I looked into fixing/repairing my radiator when it developed the dreaded crack in the plastic end tank. Turns out the end tanks are/were available separately from the core. Obviously, a couple of specialty tools are required to pry off and then bend back the many tabs holding the end tank to the core. All in all not economically advantageous as compared to the Nissens models readily available, especially looking at doing this just one time. Now, if the OEM core turns out to be that special, it is nice to know the repair option is there.

Best of luck, keep us posted.

 

Since i now operate in a very hot climate was considering this alloy radiator for my regular XK8. Some of my driving locations are taking the coolant temperatures right up to the wire in a system with no other issues. Currently using a Nissens with no issue over the past few years.

I could ask the company if it would be a direct install for my car, but figured some feedback here would also be useful. Thank you.

One thing regarding the OEM unit and its plastic end tanks is that this is an issue with the particular plastic formulation. I have replaced the radiators in Japanese import cars where it was the actual cooling tubes which were damaged/corroded and the plastic tanks were just fine even thirty years later as a rule. Thusly, eliminating them here is future proofing, and one might not want to waste the time installing new plastic tanks on a core which might be ready to leak anyway just from the years and inevitable corrosion.

 

If it was me:

• Get a quality radiator cleaner and flush/clean the system. I do this one in a while and the difference in how quickly I get heat in the car on a cold day is amazing. Not sure if Dexcool tends to "coat" the internals, but heat transfer is definitely affected over time
• Double check if you fall within the operating parameters for distilled water and Water Wetter. Back in my track days, this product had a wonderful reputation for bringing cooling system temps down without costly upgrades, ducting, and the like.
• Consider drilling holes in the thermostat plate to enhance flow to the radiator. I understand eliminating the thermostat entirely messes with flows so much it overheats, but experimenting with this seems cheap and potentially fruitful

Best of luck, keep us posted.

 

Thanks,

My radiator is actually very new as well as the water pump and all hoses, T-stat. Heater worked excellently in the much colder climate before i moved. My car was converted to a non-Dex OAT a long while back, and recently to a HOAT with excellent results. I still have some situations where i do not trust water only. Note that even with 113 deg F sustained temps, she is running at 75 MPH at 212 coolant temp with the ECU sensor matching. Stop and go, town driving at 113-115, still hovers around 217 with ECU sensor same. When the weather is 95 or less i often hover around 200-205. It is very important that the ECU sensing matches the coolant. Many vehicles have two coolant sensors. I have to get the story with this one. When the ECU sensor is higher than the coolant sensor as i saw with the Android Torque App during the route in question, this is usually a sign that system cooling capacity has been reached and heat transfer is not possible with the existing hardware.

The driving which does this is a 55-60 MPH constant climb of over 5000ft in about 20 minutes with the AC running at least 110 deg F. This is likely a corner case. I start touching the red zone and ECU temp reads 222, just as i get to the top. When i get to the top of the mountain, and turn off the AC, coolant temp drops at least 7 degrees even with spirited driving. No warning lights or running issues, just the perception of being on the edge of operating conditions.

When i had things apart for the water pump two years ago, there was no sign of scale, and the internal radiator fins are clean.

Curiously during the heatwave last month a facility employee remarked that people were overheating on their way up the mountain in cars significantly newer than mine. I saw some of them at the side of the road. Of course mine did not. Overheating is less a function of temperature but rather of when the threshold of boiling of the coolant is crossed or there is not sufficient coolant. At this point, steam can be much hotter than design intentions and lack of liquid contact with internal surfaces negates most cooling. My coolant is not being lost or consumed at all. I simply think that this is a tough test, probably not often considered, hence the newer, very modern SUVs and cars having trouble with the climb. Once again, flat roads and minor grades, can handle Death Valley and have proven it maintaining coolant temps of 217.

I think that this is a corner case and extra cooling capacity would give a better margin of error in the overall very hot climate in which i operate and one of my favorite drives.

Also, it appears that the Real Gauge Kit is truly right on the money with the temperature readings. Many thanks to its creator.

 

222 F is not overheating. A pressurized cooling system will not be boiling at 222 F.

Z

 

Yes, it is a learning curve in this new climate, and the scale of the factory gauge does not help. I am actually considering if i can mod the Real Gauge Kit or make my own which will allow a broader scale for operating temps on the factory gauge in the useful ranges.

Did you ever get that radiator replaced?

 

I am in the middle of it.

i just made a tool to cut some threads into the damaged A/T cooler line nut.

A serious hack if I ever did see one .

I took a stainless steel M20x1.5 female to male fitting and cut some slots in it like a tap has, and drilled out the center A LOT so it would fit over the flare of the trans line. Did you know stainless steel is really really hard to drill without having a vice to hold it ?

How I managed to be without a vice is a long sad story.

.
I choose that material so it might have a decent chance of cleaning out the damaged fitting’s threads.


after much cursing and some back and forth with an 1/2” impact and cleaning out metal debris countless times I was able to get full thread engagement and a solid threaded connection between the line and the radiator fitting.




Will The connection hold a little pressure ? Probably as the o -ring is doing all the work. And the damaged nut doesn’t need much tightening.

the jury is out.

im still interested in ditching the stock trans cooler arrangement and putting in a remote stacked plate cooler at some point.

So far, I’m not impressed with the Nissan radiator quality. It’s a tube and
fin design which is not as efficient as the stock stacked plate design.

It’s been mentioned on this forum that I can expect 10+ degrees F HIGHER coolant temps with the Nissen radiator as a consequence of the tube and fin design vs the stock Jaguar unit’s more efficient stacked plate design.

UGH ! I’m not looking forward to that.


Also, it’s left to the installer to arrange for some weatherstripping on the top and bottom of the radiator. Thats just plain cheap. So far it doesn’t look like weatherstripping is going to want to stick to the super thin and sharp edges of the fins.

I’m beginning to 2nd guess the decision to get a new aftermarket radiator vs a used Jaguar unit. And I haven’t even finished the installation yet, so more fun awaits .

New or used : Some drawbacks either way.

Z

 

Zray,

That is some seriously nice machine work on your cleaning tap, compliments.
If it helps regarding the Nissens, my temperatures on an XK8 went down about 4 deg when i replaced my original, so it is not lesser than that, although there might be a different capacity for an XKR original. And, you know of my recent heat testing escapades... If it were my car, i would cough up the coin for the new alloy which we are discussing unless you know some pro who can completely inspect and renew a used radiator properly, a tall order as most of these guys are long past retired.
While you have yours out, i would take the opportunity to rust proof the lower cross member. Interior access for flushing out dirt and for spraying with tubes various coatings is possible. I found it not necessary to reinstall a lower seal, and this only serves to hold moisture and debris anyway. The air getting past is actually a good thing for keeping it dry. On top, the foam used for window AC installs is excellent. Actually i removed it after a year, and it changed nothing measurable.
If you have not yet separated the rad from the condenser, my trick was to use nylon zip ties to hang it at just the right height. Once the receiver/dryer is free, one can easily move it up and down.
Best of luck with the project.