To answer your questions:

Anything green that cleary states "safe for aluminum" will work great.

That little cap above your radiator keeps the coolant pressure at 10-15psi, making it harder to boil. How does a cheap little cap do all that? There's a spring in the cap to relieve pressure above 15psi. Simple. Evan's coolant doesn't boil, so it doesn't need a spring-loaded pressure cap. http://www.evanscooling.com. The only thing you need to know when flushing your coolant is how to take the cap on and off. It's an irrelevant topic unless you get Evan's coolant.

You should drain both the radiator drain plug and the engine drain plug. I don't think the coolant will hurt anything below it. Be sure to catch the coolant in a tub, as it is poisonous to animals and they love the stuff. Don't ask me where to recycle it, though. I let mine evaporate in a place where animals can't get to it.

After that there are a variety of flush methods which you can look up yourself. One involves draining, refilling with water, running the engine until warmed up, then drain and repeat. Another involves a hose for continuous fill/drain while the engine is running. Others might drain and refill with 50/50 antifreeze/distilled water, without rinsing out the cooling system.

With flush n' fill the process isn't any different, except you add the flush n' fill stuff while running the rinse water through the cooling system.

 

thanks for the answer. i guess ill let the engine drain out onto the parts and just spray them off after im finished.

 

Yeah, do that. The coolant is harmless to the parts. If anything the coolant will protect the parts from rust.

Let me know how it turns out. Last time I drained my coolant I didn't know about the engine block plug. I had to refill with water several times to dilute the remaining coolant, and there was still a little old coolant in the mix.

Here's the gist of one guide I saw:
You'll need 2 gallons antifreeze, plus atleast 6 gallons distilled water. You need distilled water because tap water contains a small amount of dissolved sediment, which can build up if you put enough tap water in your radiator. I've seen it happen. The coolant reservoir was half full with what looked like fine sand or dirt. Even after I cleaned it out sediment kept going from the radiator/engine to the reservoir.

1. Drain (both plugs). Then remove the radiator cap to let air in and make the coolant drain faster. You'll need a siphon to empty the coolant reservoir.
2. Refill with distilled water and close everything off.
3. Run the engine with the heater on full blast until the car warms up, plus 10 minutes more.
4. Drain.
5. Mix distilled water and antifreeze 50:50. Refill with this mixture.
6. Run the engine for a while, then refill again, if necessary. Finally refill the reservoir to "F", if necessary (excess coolant from the radiator will blow into the reservoir).
7. Check your coolant level every once in a while over the next week.

 

Oh yeah, you need to remove the air bleeder plug when filling. It's that plug near the radiator that you take out with a Phillips head screwdriver. Otherwise it won't let air out and it will be hard to fill the coolant system. When replacing the plug, don't over-tighten. It is easy to break this old, brittle piece of plastic. If you break it you can usually replace it with a radiator drain plug, though the fit isn't always perfect.

After filling, closing everything and repeatedly squeezing a radiator hose helps push air bubbles to the top. Do this and you'll find you'll be able to cram another quart of liquid into the system.

 

wheres the air bleeder plug for the s5 n/a? the manual shows it next to the intake box but i dont see it on my car. thanks again.

 

There is no bleeder plug for an S5. It doesn’t require one. The filler tube is the highest spot on the system. All I’ve ever done is to remove both the block plug and the radiator plug. When the coolant stops running out, I put the plugs back in and refill. I’ve never used a flush kit. With regular coolant changes, I don’t see the need for them. That, and I’ve heard stories about harsh flush kits. Whether they’re old wives tales or not, I can’t say, and I don’t intend to find out. I don’t even flush with water. If the coolant is changed every year, the little bit that’s left won’t matter.

 

well my coolant looks orange (and im sure it was once green) meaning, its real real bad. i think a flush is required but i will surely keep it a yearly routine after that becasue i would love me car to last 376ks. thanks and GO HEATS!!!!