I would just do a drain and fill, especially if using premixed. Then in a few weeks do another drain and fill. Then, possibly do another drain and fill next year and not worry for the next three years or so. I would probably use Zerex Asian P-HOAT (POAT) premix. Napa carries it. If I could not find any Zerex Asian, I would probably spend the money on the Toyota super long life pink premix. Motorcraft has a deep green Asian formula that is a Phosphate (P-Hoat) which would probably work too. Another interesting coolant is Peak Global that comes in premix and possibly full strength, but am not 100% comfortable with it.
If you use full strength, use distilled water for mixing. If you feel the need to flush, just fill up with distilled water and run for a few minutes, then drain in a pan for proper disposal. The problem with flushing when using a premix is dilution of the coolant since you cannot get all the water out.
This is how I usually do a coolant change. It might not be correct, and I might make things more difficult than it needs to be. Do a search for the proper procedures. I have not actually done a change on a Vibe yet. Hopefully someone will chime in. When I do, I will just drain and fill and use premix. Much less hassle:
If using a full strength, fill first with the right amount of coolant, then top with distilled. Burp the hoses to get air out and top off. Mix with right ratio in overflow. Start car and let run, burp, and top off at radiator. Might take a few minutes for thermostat to open. When it does, the level usually drops and at that point heater core hoses will be getting hot and heat will come out of the vents when turning on heater. Be careful. When you pretty much have used up the right amount of distilled water into radiator, Turn off engine and put radiator cap on. If you did a distilled water flush, there would already be distilled water left over in the system that you did not get all the way out so you might not be able to use all the measured distilled water. This is why I always put in antifreeze first, instead of premixing and trying to fill up. Let run for a while and build up pressure, checking overflow tank and top off. Let cool down and carefully take off radiator cap, stopping at first "click" using a towel if not sure if all the way cooled down. Then proceed in removing the cap. Burp and top off if needed. but be careful not to squeeze too hard and splash coolant out. Recheck a couple times over the next few days.
Not sure off hand how much the coolant reservoir holds at the cold line. A good guesstimate or actually taking it out and measuring it might come in handy, since I think the total coolant capacity has that figured into the equation.
I believe there is an engine drain petcock that would help in getting most of the coolant and distilled water out. Most people probably just disconnect the lower hose instead of risking damage to the radiator drain petcock, but I would probably do both.
Here is a post I did a while back on antifreeze/coolant. It needs to be re-written and updated, but I have not got around to it. Judging by the overwhelming response it got (crickets), probably not worth the effort.
viewtopic.php?f=28&t=36762" onclick="window.open(this.href);return false;
I am not a professional mechanic, I just play one on forums.
2010 Vibe 1.8 auto, fwd, base, air, preferred package, cargo mgt, cargo cover, ultra white.
