Engine coolant appears to be leading from the area where the large hose goes to/from the radiator to the engine. At first, it looked like I may just need to tighten the clamp on the large hose, but that didn't do the trick. The first picture below shows the area from up top, in the red oval. The next picture has the red arrow pointing to where the leak may be coming from. I'm guessing there is a gasket along that seam, but not sure. It looks as though it has leaked down, or may be leaking from an area down lower too. I'm sure this is something that I will need to take to the shop to get fixed, if it needs to be fixed. I'm just curious how serious this is and whether or not driving it like this will do greater damage to the engine over time. Any input would be appreciated. This is my first Jaguar, and I plan to keep it for at least a few more years.

 

If it's leaking from the thermostat housing, stop now, open it up, and replace the rubber seal (I get so mixed up these days between cars - it's crazy). It's either a rubber gasket that looks like an Oring, a big one, with a split in it to receive the thermostat edge all around, OR it's just an oring that sits between the faces of the housing thermostat behind it OR, lol, it's a gasket - old style... I need a nap. I'm sure it's a rubber Orings style seal - one of the first two.

The housing shouldn't really need all that RTV, if any at all... RTV can actually get in the way of things sitting right... Is that your doing, or the other guyz?

 

I think if it is leaking there its the thermostat gasket which is just a regular gasket material gasket. While you are in there it would be a good time to change the thermostat.. If I recal it is a 184 degree F. Why all the sealer is hard to say. Maybe the prior owner stripped out a bolt or cracked the housing but that amount of sealer could be the cause of the leak.It is in a awkward place so you may have to disconnect some of the other hoses to get to it. Good luck.

 

KY... If you Google "Jaguar XK8 Thermostat Seal/Gasket" along those lines you will see a photo of the new seal. It's basically (at least on the 1997-02) a rubber seal (looks like an oring) with a split in it that the thermostat edge rides in... Then, there may also be a paper gasket. The rubber seal fits into a groove between the faces of the halves of the thermostat housing.

In your profile it would help if you listed the year of your car.

 

This is my first Jaguar and I'm just learning about "newer" cars. I've got the 1966 Mustang figured out at this point, but not the XK8. So are you saying that the red stuff isn't coolant leaking? It is some sort of sealer? If so, it was either the previous owner, or the shop that replaced the throttle control unit or water pump. It sounds like maybe I shouldn't worry. It does smell like something is burning in the engine though.

 

Ok. Now I'm wondering if it is even coolant that's leaking and not just sealer from previous work. I updated my profile. Thanks for the heads up. I may have to look around and see if it something else burning.

 

Got water, lol?
If I see a puddle, or smell something like sugar burning, I worry and get to looking. Might just be old coolant from a job not so well done (past) burning off. It's a distinctive smell... Ya haven't told us much about the car...

It's a sealing (silicone) paste called high temp RTV...