I've been experiencing slow, intermittent coolant leak basically since I got the car over four years ago.

Sometimes I would go several months without losing a drop, and then once in a while the level in the expansion tank would be down at or just below MIN.

At first I thought it was a simply a bad cap on the expansion tank, since that's where I was seeing residue.

However, after the latest attempt to diagnose, my local specialist shop determined that the fluid was leaking from the radiator drain plug, after they pressurized the system and found where it was dripping (note: I had taken the issue to the dealer previously, but they were unable to find anything - perhaps the issue simply wasn't as progressed at that point).

Here's a screen cap from the quote:




Initially they only suggested replacing the plug. HOWEVER, it seems that the plug alone is quite difficult to source (?).

I'm not against replacing the whole radiator in principle, but it's also pricey enough that I'd like to know if there are other suitable options.


So - does anyone know where to get a radiator plug?


PS: if replacing the radiator is indeed the best option, are there any other prudent services/repairs/mods that could be grouped in with more or less the same job?
Thanks!

 

Presumably you mean the fluid is just seeping past the plug threads?
Before trying anything else, why would you not try simply sealing the plug better?
You have a couple of options.
You could use a liquid/paste sealer like Rectorseal (used for diesel, so should be OK with coolant).
Or, even easier, simply wrap the plug threads with the diesel version of teflon tape.
The last thing I would consider is the significant cost of replacing the whole radiator assembly.

 

See that’s what I thought at first! Seems like the sanest starting point to me.

Unfortunately I have no tools or space to work for myself so I’m at the mercy of whatever the local places are willing to try (they often seem gun-shy, presumably for fear of an owner giving them grief over an ineffectual/deleterious repair attempt).

A new plug by itself does indeed seem hard to find.

 

Luc:
A new plug may not solve the problem.
If it really is leaking at the drain position, there are 2 possible causes that I can see.
Best case: the threads are damaged on the male drain plug and most likely also on the female inlet.
So just replacing the male alone will not solve the problem. Using teflon tape or sealant should fix the problem.
However, you have to ask yourself how the threads got damaged in the first place - most likely because a tech. cross-threaded when replacing the plug.
Worst case scenario: the same tech, applied too much torque, stripped the threads, and might have caused a hairline crack.
Three is no way I would consider replacing the radiator till I had exhausted other options.
While not a fan of radiator sealants (added to coolant), even that might be worth a try.

I will state that I am not a mechanic, though I did get to deal with numerous funky issues on my large trawler.
Perhaps someone with more specific knowledge can help.

 

Perhaps somebody can comment but perhaps the plug is a part common to other Jaguars.
You might be able to source one on Ebay (see below), though I must admit to not knowing what it even looks like.

https://www.ebay.com/itm/29337350257...ABk9SR9L85YnDY

 

Hello everyone,

I had to replace the radiator due to the same issue. When upgrading the intercooler, I used the radiator drain plug during the initial setup for the job. I do not believe you can replace the drain plug due to the poor design of the radiator. Although the core of the radiator is aluminum the sides are constructed with plastic, so you have a plastic drain plug threaded into plastic. On my type R the plug could not be removed meaning its designed to drop down once unscrewed if that makes sense.

After the intercooler, secondary coolant pump, pipes and hoses were replaced I lightly pushed the drain plug back in and gave a half a turn with a standard flathead then filled the system. At this time, I discovered that the drain plug would not seal and was having seepage similar to what you have.

You could try some type of sealant (JB weld/etc.), but in my opinion there is too much risk. If you decide to seal the plug and the seal does not hold you could lose the engine due to overheating leading to another topic of poor design (lack of real time temp reading).

The radiator at $400 can be changed with a set of stands/floor jacks. If you decide to go this route let me know and I will provide the painful lessons learned when I changed my radiator/ intercoolers. Lastly, I would recommend DIY because you will not only learn more about the platform it provides a level of confidence that the job was done correctly while saving a significant amount.

 

So it sounds to like to me, if one is wanting to drain the radiater say example for a flush, you would be better off taking off the radiator hoses and making a mess vs having to find a new plug or worse yet, a new radiator!

 

There is a drain plug that screws into the block that I discovered at a later time. You can disconnect a hose, but that can cause issues as well because the hose clips weld themselves to the rubber hose and, in some situations, will actually remove some of the rubber. The clips can be extremely difficult to remove. With my car, I had to actually cut several of the hoses out for removal, and in the end, just replaced every hose.

 

Just another basic design anomaly / flaw!!

 

Thanks for sharing your experiences.

Where did you find the radiator? I'm seeing prices in the 700-800 USD range (mind you I've only looked in two places so far).

Obviously I'd rather not replace the radiator if I can avoid it (seems like a $corched-earth approach to me), but based on the replies it seems that I can't rule it out as ultimately being the optimal solution.

 

I bought it from Harper Jaguar and just checked the price. They are currently $320.00 part number T2R1842. The replacement was not too bad but then again, I had the car torn apart. I have a bad habit of the “Since I’m in there” mentality that turned a simple intercooler upgrade into replacing both intercoolers, all hoses and pipes, water pump and thermostat housing. The same with sending the supercharger out for porting turned out to replacing plugs and injectors. It’s a curse.




I will drive this until I can't drive anymore.

 

Ah yes, I forgot about markups.

I've put some sealant into the system for now.
My next step will be to find a shop that's willing to install a radiator that I've bought myself (100% markup? I get that they need to keep the lights on, but no thanks!).


PS beautiful car