After almost a week of trouble free ownership of my 2000 XK8 and in a very good mood after watching my beloved Bears finally get a win over the Buffalo Bills, I decided to go looking for trouble in the garage. The only issue I have with the performance is that there seems to be a slight hesitation when I try to “get on it”. I thought I would check out and clean the throttle body. After removing the breather tube and look at the throttle body, I thought it seem very clean. Then I opened the throttle valve I couldn’t believe the black build up under the plate. I cleaned it as best I could with a rag and my fingers as per the link to maxperformancecars.com (thanks for the link) put it back together and it seem to run better although it is too early to be sure. Is this build up in the throttle body normal?
Also another problem I might have found is that around the thermostat housing there is evidence of a fluid leak. I have seen no “fluid” just an orange residue that seems to be coming from the cap at the top of the thermostat housing. I have not yet removed the cap as the engine was still hot when I checked it but most of the housing is covered in this residue. Is this a sign that the plastic thermostat housing should be replaced with an aluminum after market one, or am I reading too much into this condition?

 

Yes, I have also seen orange residue as evidence of a coolant leak. I have also seen some shiny wet remains of fluid after returning home from a drive. The engine is hot and the coolant is still under pressure after turning off the engine. Sometimes you can smell the slightly sweet fluid around the front of the car.

FYI, I have had the thermostat housing, coolant outlet duct, and several different heater hoses changed to jaguar OEM parts.