Well, I have not been here around a lot since early this year, but enjoy driving the XK8 without any hassles ... until last week that is .

I can use some insight, as I have a problem I can't find anything on the net or forums, maybe I miss the correct wording though.

Jaguar XK8, 2003, 4.2L N/A.
My right upper radiator stud is leaking, the plastic part attached to the radiator itself.
Today I removed some stuff, then cleaned all up on a cold engine.

After start, as soon as the thermostat opens (and I guess pressure builds?), the stud slowly fills up from the inside, then overflows through 2 holes halfway.
I can't see any damage or crack, but it is all pretty much hidden.

Anyone experienced this before, any ideas or suggestions?

 

Hi, it is just a trim post for fixing part No. 9, i've never heard about leaking from the inside. Because it is part of the pricey cooler i would try to seal it with a suitable glue.
Probably it will be nessecary to drain a few liters of Coolant in order to get the post inside dry and clean.

If that doesn't works plastic welding seems to be an option.

Goog luck, Fritz

 

see if you can find a vacuum cap that will fit the tube and zip tie it in place. When I purchased a replacement radiator a few years ago, the one vent line is no longer used in the later MY X100's. I filled the system with coolant and immediately had coolant pouring out the vent line. The quickest solution was to get some of these, find one that fit and zip tie in place - has been working like a champ since.

https://shop.advanceautoparts.com/we...=vacuum%20caps

 

I've seen this on another radiator in my daughter's car. It was fixed with a bolt threaded into it. I thought that was odd, "Why would anybody put a bolt in a fixing peg?" But when I pulled the bolt out it started leaking coolant. I put some sealant on the bolt and screwed it back down and it's never leaked since.

 

Thanks for the replies.
I can't open that link, but I guess I can imagine what you are saying.

Seems the exact same issue then .... thank you for replying, not sure to be happy or sad I am not the only one .

Thinking things over yesterday, and considering the price of a new rad, transport and import charges, I have decided to take my chances first.

A bolt might work indeed, but I thought about making a plug, as the peg is hollow, and quite long.
Covered in JB weld or sealer or something, held down by friction or by a wedge through the 2 holes already in the peg.
I can't see how that should not solve the problem of the leaking from inside the peg, and totally invisible.

It might start to leak from around the peg though, I simply can't see right now if that is the case.

 

Wow! And here I thought mine was the only one leaking there! I thought it was from when the previous previous owner hit a deer! Maybe not 😲😲😲😲😲😲

 

Yeah, seems you are not alone
It's hard to see, but it seems there are 4 plastic welding seams coming together just under that stud, it might be the weak point.
So how you fixed it?

I just made 2 wooden plugs of ~8mm, rounded the tip, and drilled a little pilot hole where the holes in the stud are located.
Cleaned up the inside of the studs, roughed them up, covered everything in high temp sealant, and pressed them in.
Then locked them with some little screws (which will be covered by the rubber grommets once installed).
Will let it settle for 2 days, then cut off the top, paint it matt black, no one will ever notice.

Good case scenario: problem solved, outlasting the car,
Bad case scenario: it will leak around the stud ....
I give it a 50/50 chance.

 

Good looking solution/fix.
Stainless steel screw's...+1
With your fix do keep in mind that wood will expand/contract with moisture/heat.
Hopefully the high temp sealant will of sealed the wood from the moisture.

 

I figured that wood will behave a lot more like the plastic / nylon, better than jamming a solid steel bolt into it.
And it is semi-hardwood, I can assure you that will last a lot longer than the whole car, leaking or not

 

Eric - nice job on the repair. Sorry link didn't work - here is a pic

 

Take it as a sign of the universe that you need a new radiator. These brittle, aging plastic end tanks are not easy to fix. Remember, a failure of the cooling system means you are stranded somewhere and looking at an expensive tow home. The Nissens radiators are not terribly expensive for this car at the rock place. FWIW, I had the same symptoms for a while on my old radiator, but the root cause was an actual hairline crack around the hose inlet just below. Somehow this post would slowly fill up as well, go figure.

The radiator replacement job is not fun, but the A/C condenser can remain connected/sealed the whole time, contrary to what the workshop manual says. Triple check the fittings for the transmission cooler, the "gender" changed between the earlier 5 sp, and the later 6 sp. "Unfortunately", this job opens up space at the front of the engine, so be tempted to replace the idler, tensioner, water pump, belt and even oil cooler lines. Look into the whole thermostat, sensor and pipe assembly if you have not done so already. Ours is plastic and likely at the end of its service life. From memory, the (cheap) sway bar bushings become super easy to replace with all that space. Be sure to put the hood in service position for access.

Best of luck, keep us posted.

 

As always, your reply is spot on.

Still, I decided to take my chances for now, spending several hundreds for a new radiator / transport / import duties can always be done.
The fact that it is a hairline crack, and that it seems to be on the exact cross of all plastic parts, might give me an other option.

If the above repair does not work (I let it dry for 48hrs before trying), I will probably drill the wood out.
Then drill a small hole at the exact spot where all those seams come together, I think I can just reach it through the hollow stud.
Then fill that hole with sealer or a small bolt / sealer.

I should be the first one to replace the tank with an improved one, but it seems you can't buy those side tanks separately.
As this is basically just a stupid manufacturing issue playing up, I rather just solve that than replacing a perfectly fine radiator.

 

That is the other approach. When I did research a while back, I definitely found these plastic end tanks separately (check www.thermprocesses.com). Not terribly expensive, but then you need a couple of special tools to crimp the tanks on and off. Tanks, tool and shipping plus down-time was a non starter for me. Of course, if you look around, I am sure there are radiator repair places that can do this for you. Nissens part was just too competitive over here to pass up. Part of me wished it had not been, so I could collect a new tool and gather another skill. Oh well. The extra possible complication is that the cold side of the radiator houses the transmission oil cooler, which could complicate the end tank replacement, unless it all comes together already.

As usual with any repair based on goop, besides the intended sealing effect, think of the possibility of any of it getting loose and going places...

Best of luck, keep us posted.

 

Same problem when I replaced the radiator in a 01 XK8 a few years ago. That top port was open on the new radiator, believe it was a Nissan. Closed it with a cap as shown in a post here. Of course after spilling antifreeze out of it. As I recall the radiator was very reasonable on Rock Auto..

 

I'm keeping an eye on it for now, I haven't seen any real leaks, but I haven't been driving it as much since I've been driving my XJS since it's been nice. I figured I'd just replace the radiator if it starts leaking more. I know, bad way to go about it, but oh well

 

Thanks for the link, never found that one.
I did not cross check part numbers yet, but I see a tank listed for the XK8.

And ... with the way I will solve it first , there is zero chance of stuff inside the radiator, I promise

Yeah, I am a big fan of Rockauto, and saw a Nissin listed for USD. 220 or so.
Still, getting that imported to the island here will set me back at least the same, probably more.

Well, I will keep this post updated as I go along.

I will start up the car tonight and see how the first attempt of repair went ...

 

ericjansen,

Let's see how your wooden dowel repair works. It'll at least buy you some time, until some other plastic bit of cr$p fails in the engine bay and you can do the radiator swap out at the same time as the other job.

 

Always love people with a positive look at life

 

Well, I let it dry and harden for some days, as we have bad weather anyway.
Then cleaned it up, and ran it stationary till the full radiator was hot both sided.

At this point, it was clearly leaking before, but so far everything stays dry.
Real test will be a drive up the mountain, then time ... we will see ... first need that typhoon out of the way ...

Now an other question; with the plastic radiator cover removed, I had a look along the radiator down.
Quite a mess there, leafs, sand, feathers, dust, and the likes.

Would like to clean that up, and should normally use a garden hose to clean the stuff out reverse (forward).
However, this being a Jag, what you think?
I can be careful, but some equipment like the fan motors, some connectors, etc are in the way for sure.

 

I took her out for the last 3 days, and so far so good .... no more leaking.
I concluded my mission succeeded, and the chance of springing a new leak is about the same as for all you other XK owners out there -- sooner or later -- ....

Thanks for all replies, highly appreciated!