This is on a 2006 XK8, with 4.2L engine: on the plastic thermostat housing there is what looks to be a plug of sort, on the far left side, nothing connected to it. There is a small coolant leak here.
I have replaced the entire assembly once already some years ago; am I really looking at replacing this again? Or does this "plug" unscrew and just needs a new O ring? Not sure how I would ever get this "plug" out, not like it has anything that any tool I have will work.

Thanks,

 

Decided to do a "got nothing to lose" approach.....cleaned the coolant off, applied RTV in this area.....will see.

 

Get the aluminum replascement.

 

To my knowledge there is still no aluminum replacement for the 4.2 engines....

 

None that I am aware of.

First attempt of the RTV "fix" was not 100%, had a very small leak at the very bottom of the plug, Cleaned-off, applied RTV to this area. Will see once again.

 

I doubt that will work with the cooling system under pressure. That may be a plug that fuses by friction from spinning.

 

As expected the RTV "fix' did not work. At the bottom of the "plug" circle there is a raised area that coolant continues to drip-out, almost like a weep hole in a coolant pump of past. Tried applying RTV inside this, but no luck. Looks like replacement (again) is the only route. I checked my logbook; replaced the thermostat tower/housing in Sept of 2017 at 74386 miles; less than three years and 25k miles......crap parts.

 

Sorry to hear that. It certainly confirms that utilizing plastic parts in a cooling system to save money eventually penalizes the owner....

 

I was searching around for prices/in stock thermostat towers....came across one on Amazon that had the lowest price. There were two reviews with one saying the part lasted a year then started leaking at the "plug". The listing says it is genuine Jaguar part....probably not....but I am not having much hope in getting a tower that lasts very long.

 

I installed my OEM tower (officially called the Coolant Outlet Duct) in late November 2014. No leaks thus far, knock on wood. Part No. AJ89486. I paid $115 after a bit of negotiation at the local dealership (their asking price was $147 at that time)....

 

You can get an aluminum one for under $ 100.00

 

Please provide a link. I think you are looking at the 4.0 L part. It will not fit a 4.2 L.

 

I am, but, I just checked out my 2001 XKR and 2000 XK8 I do believe that the entire assembly from the XKR can be used on the XK8. You just need to incorporate the hoses and goose neck coming off the engine.

 

This thread is about the 4.2 L engine 2003-2006, you are referring to the earlier 4.0 L 1996-2002.

 

Mea culpa

 

I do not remember where I obtained the Coolant Outlet Duct from....probably not a Jaguar part even though I used the AJ89486 number to source it.

I will get a new one from an actual Jag parts house for sure this time....I have learned my lesson!!

 

I don't think there is an aftermarket one. I replaced mine three years ago and again less than a year after, both times because they leaked along the molding seam at the top.

 

Quick update to this: I did find an aluminum tower kit from SNG Barratt that they say replaces all the plastic parts. Have ordered, be here tomorrow, will see.

 

If it fits, please provide the part #s.

 

Another quick update here....no the aluminum thermo kit does not fit the 4.2L engines. It is now listed in the Marketplace.

Getting another plastic outlet pipe, getting it from Terry's Jaguar Parts.