Hi everyone. I just finished replacing the coolant pipes and hoses in my 2010 xk NA 5.0L. I buttoned everything back up but as I was getting ready to fill the system back up, I realized the radiator drain plug wouldn’t seal. The service manual states 2nm and I was very careful when loosening the plug for the drain and even more careful putting it back on. It feels like the threads are stripped or deformed but I’ll have to completely remove the plug to be sure. I know, I know. Should not have messed with 15 year old plastic.

I used a vacuum filler and tested if the system leaked and it would slowly lose vacuum. Unfortunately I had to fly out of town so filled the system up so it could be moved in a pinch and left feeling disappointed.

For now, the system is full and doesn’t leak when cold but as soon as the system is under pressure, it drips a drop a second.

I am mentally preparing for the repair when I get back and want to get parts ordered. Few questions:

1. is the female threading of the radiator metal or plastic. Hoping I just need to replace the plug and not the whole radiator.

2. does anyone know what the OE equivalent is for the genuine Jaguar plug? Part number is jlm20622. Found another thread reference Dorman 61138 but can someone confirm please?

3. any tips ok removing the plug and replacing? Do I just tug until it comes out? I see it has a barb like prong to hold it in.

 

Yes I was the one that found the Dorman part and posted about it. I am surprised you found a part number from Jaguar because on my 2014 XJR with the 5.0L SC engine you have to buy the entire radiator as that's the only way Jaguar will supply the part.

Here is a comparison of my stock plug and the very cheap Dorman #61138. About $6 at any parts store or on-line. My local O'Reilly's had it in stock so must be used on millions of common Fords.



A couple of tips to help? First use the biggest flat blade screwdriver that will fit in the slot of the head in the plug. The tighter fit helps prevent damage to the head. That's why I had to replace mine as I damaged the head using a smaller flat blade screwdriver. Next the plug will turn a bit and then lock up solid. Use some WD-40 on it and slowly work the drain plug back and forth a bit. As the WD-40 creeps in the plug will start to turn very easy and with no damage. You can see the rubber gasket in the above picture under the head of the plug and that's what locks the plug up.

Here is the damaged head that had me looking for a replacement. The new part is on the right.




A big thank you to Hafren for his prior thread on this. Sorry I can't find that thread at the moment.

To answer your question. No the barb does nothing and the plug just threads into place.
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hi yes your post was the one I was referencing. Thank you! In the photos it appears that the thread size appears slightly different or are my eyes playing tricks?

 

I checked it every way I could. It seems to be identical and it works 100% in the radiator. I have been running it for several thousand miles now.
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