My lessons learned from changing the coolant on my 2006 Federal Elise (non-SC).
1. If youíre not getting fluid out of the radiator bleed, you may not have circulated enough fluid. I started the Elise hoping it would push the fluid through, but instead it just got hot really quickly.
2. I had to apply pressure to the header tank. I used an inner tube, with a kitchen bag closer to seal off the overflow pipe. The first few times I filled and pressurized, the tank level dropped and I could hear the gurgling of air. After a few goes, and over half a gallon of extra fluid the fluid would flush around and the level remained stable.
3. Running the engine to flush the fluid took quite a while to get hot enough to active the fan. (Mine started at 206f, shut off at 200f.) I could tell the fluid was circulating from the color change as I was using Peak Global Lifetime, a different color from the OEM.
4. I only got about 1.5 gallons/6 liters out, which was less than I expected. Next time I might use the air pressure to flush more out. (Thoughts?)
5. Opening the block drain is a real pain (literally). I only got less than a pint/0.5 liter out, and it was nice and clear. I took off the lower aero cover, which the shop manual doesnít mention. I suspect that thereís so little coolant lost you could skip that.
6. Overall, the coolant that came out was clear, which Iím hoping is a good sign. (My Elise had no history, so the coolant could have been in their for 9 years.)
7. I tried the trick of accessing the radiator bleed via the top grill, but in my model itís really hard to reach, so I ended up taking off the wheel arch liner as well.
8. I didnít flush the existing coolant with water, which Iíve seen some folks do. I didnít want to leave an unknown amount of water in the system, and I could only find pre-mixed coolant so I couldnít compensate anyway.