All, I bought a 94 Jaguar XJ12 from a friend of mine back in late 2018. It was kind of an odd ball sale as he had some medical bills to pay for and did not want to be spending on a bunch of cars. I was not looking for a Jaguar at the time (this is usually how I buy all my jaguars) but decided to buy it anyway. It's been stored in the back of my building since until I decided to sell it so I pulled it out and washed it and then decided that I should drive it.

In any case, I've been spending the past couple of days shaking it down. I had to replace the rear shock which I took care off and and let it idle for about 45 minutes. It ran fine with no issues so i took it for a spin to the store to get some groceries and gas, then to grab some sandwiches at a place that was offering a drive through service. I was talking to the franchise owner about the car (about the same age as me so college in the early 90's) and he was telling how much he liked these cars. He then told me that I was leaking coolant and sure enough, I was dumping coolant so I quickly drove back to my hobby shop and parked it. There was still some coolant in the expansion tank so I don't think I ran the car dry and the temp did not increase past normal.

I could not see any visible leaks, although a lot of coolant was dripping outside the sandwich shop from right at the front of the engine, so I suspect that the radiator may have failed at the tanks.
I checked online and there are not many people selling OE radiators. Although I did see the following aluminum radiator on ebay.

Anyone have experience with these?
https://www.ebay.com/itm/3-ROW-Aluminum-Radiator-For-76-96-Jaguar-XJS-V12-XJ12-5-3L-6-0L-MT-US/333176729755?f

Anything else to check?

Thanks

 

Go to the Jaguar Classic parts catalog on line and get the part number, then google around for an aftermarket unit if a replacement isn't available.

Of course it would be a good idea to check if it is actually the RAD and not something like leaking hose, gasket or stuck thermostat first!

If it is the rad, and it can't be repaired, see if the same rad is fitted to any year of XJS - there are a lot more 12cylinder XJS's out there than XJ81's.

Larry

 

From my own small bit of experience with it, there are several small hoses and metal tubes up at the front. It would be worth checking closer, if only for your own information.

 

The water pump is a likely suspect too. On the V12 it's a large two-part assembly with two gaskets. If you have or can devise a means of pressure-testing the system while cold, that often makes it much easier to see a leak from the water pump, radiator, etc. With the engine hot and running, coolant leaking at the front of the engine can be blown in every direction and dissipated by the cooling fan. Don't pressurize the system past about 1 bar / 14-15 psi or you may risk damaging brittle plastic parts.

Cheers,

Don

 

Thanks all. It appears that the XJ12 (XJ81) uses the same radiator as every other V12 XJ and XJS model but the part does not cross reference to any other supplier so it's either the aluminum radiator that I liked in my first post or a genuine one which is plastic and at least twice as expensive. I'm going to jump over the the XJS forum and see if anyone has experience with them.

Thanks

 

Following up on this thread, I stand corrected. The 6.0 XJ12 radiator is completely different.

 

We wait with bated breath. Have you found a replacement radiator? Are you good to go?

 

I bought a used factory radiator that appears to look the same as the original radiator but with aluminum tanks instead of plastic tanks. I ran into another issue though. It appears that sometime in its life, someone bottomed out the core support. Probably from going into a parking spot nose first up against the side walk. It pushed the core up and back a little bit, but enough to cause fitment issues making it impossible to connect the temp sender. I'm going to try to pull it today and straighten it up. I'm beginning to wonder why I didn't go with my gut and dismantle this car instead of trying to fix it.