1999, 85,000 miles, and its running very well. Replaced worn transmission hoses and the transmission filter. Noise from underside the car turned out to be anti-sway bar bushings that were shot. I can find no record of the car's radiator ever being flushed and the fluid replaced. So what can a radiator shop really do with this model. I'm guessing the old days of taking my old Ford Mustang into the radiator shop and they would back=flush the entire system is not appropriate for this car. With all the various hoses and valves, etc. I wonder if it would even flush? Therefore, if that's the case, what do I ask my nearby radiator shop to do? I think new fluid is called for beyond a doubt. To they then just drain the cooling system and call it a day? Again, looking for advice from those far more experienced then myself.

 

The radiator was recently out of my 1998 XK8 (84k) to do the tensioners so I gave it a good back flush with a garden hose until it ran clear. There was a lot of sludge when I initially drained the old coolant (see the photo) but I cannot explain where it came from. Possibly the antifreeze types got mixed at some point - who knows?



Anyway, with the radiator reinstalled, I pretty much followed the procedure here except I did not use a chemical flush product. I just kept repeating the fill, run the engine and then drain off procedure (with all the usual safety caveats). I decided to go with a G-05 coolant for my particular model year. I have also ordered the Real Gauge mod so that I can keep a closer eye on the cooling system - well worth the money for the extra peace of mind in my view.

This Jaguar TSB describes the full chemical flush procedure as another point of reference.