Perfect, the RMI25 will deposit any sludge right into the tank, I have used it to clean the hell out of some old radiators. The slime once in overflow cannot leave unless you pull it out. Good news, if nothing ends up in the overflow, there was no damage. RMI25 is that good. The sludge will float, so you can scoop it out or pull the tank off and dump. Best feature, rmi25 binds to rust and pulls it out as well. RMI 25 also replenishes additive package. So I never change my coolant, I just add 8 ounces of RMI25 every year to me and my wife's 2009 rav 4. Coolant never goes bad, only additives deplete. When additives deplete and you have RMI 25 in the system, any problems will always show in over flow tank so long as you add it once a year. So I don't recommend this for the forum, just telling you what I do. I have a 2010 and my coolant is still purdy orange, and I add RMI25 once a year and plan to not change my fluid ever. unless I get a problem then I'd flush I also check my radiator 4 times a year, just lift the cap because if there is any problems it would show up on the top of the cap as well as overflow.
These are pics of visa versa, dex clone added to a system that used old prestone green. The sludge is also rust that was pulled out. See the overfow. Notice the color of the coolant, that is your problem when they mix stuff you get something in between either coolant. Clearly, they just mixed two coolants. That damage was not oil, but slime from using two coolants in a non pressurized tank, and the rust that also came. The only reason this sludge came out was because of the RMI25, without using it the sludge would have just eventually choked or corroded the system.
Air is the enemy, any O2 in a system with mixed coolants, you will have damage. Even in systems that has the same coolant, if it is HOAT or OAT damage is coming. It is why the industry has gone to pressurized tanks.
