[Brianj1992]

About two days ago I redid the timing belt and water pump in my 2011outback. But I accidentally used the green non premium coolant instead of the blue Subaru coolant. Obviously I’m going to drain it today and replace it with the Subaru blue coolant, but is there a proper way to flush the system out?

Any tips will help, thanks!

 

[eagleeye]

get a new OEM thermostat and OEM rad cap too. if you have not already done so.

when you open the bottom hose, and drain out the green. use a hose and flush the rad. and the overflow bottle (maybe get a extra chunk of blue out if you did not rinse before).

you will leave a little bit in the engine. rarely does anyone actually open the ports to let that out if the engine is not being tore down.

but not to worry, the traditional green is compatible with the super long life blue.
so if you don't do a perfect job, everything will actually be fine. (in the owners manual it says you will loose the long life qualtiy of the blue, but ....after the original cycle of the blue is gone, the change over lessens anyway).

2011 Subaru maintenance schedule and new car break-in period

contains the following on note 5:

Subaru Super Coolant. 1st replacement interval is 11years/137,500 miles (220,000 km). 2nd replacement interval is 6 years/ 75,000 miles (120,000 km) after the 1st. If towing replace more often. Use Subaru coolant only, do not mix with other types or it will reduce protection

 

[Pilot1226]

Subaru Super Coolant. 1st replacement interval is 11years/137,500 miles (220,000 km). 2nd replacement interval is 6 years/ 75,000 miles (120,000 km) after the 1st. If towing replace more often. Use Subaru coolant only, do not mix with other types or it will reduce protection

Hey Eagle,

I'm thinking I want to keep my Gen4 a little bit longer-term than I was originally expecting to. What is your opinion on the acidity of the coolant - 11 years/137.5k is a long time... Would it be more prudent to consider changing it around the same time as my timing belt/water pump service anyway around the 105k mark? (They do have to drain the coolant anyway when they change the pump, don't they?)

I also saw some test strips to check the PH on your coolant on Amazon, but I haven't bought them yet. Was just thinking that the acidic coolant seems to be the #1 killer of the gaskets, so I was thinking anything I can do to preserve the HG would probably be good for me in the long run. (When I do the coolant regardless of mileage, is it a good idea to do a new OEM cap & Tstat like you suggested anyway? I think I was going to ask they do a new Tstat when I did the TB service, too.)

 

[eagleeye]

maybe look in the 2010-14 section with people in the same boat,

I remember asking @brucep such things a few months back.

but I am in 2000-2004 land with my cars...so I don't have to think about super blue and when to change it in mine.

 

[brucep]

Flushing the cooling system would require draining the fluid. Open up most of the hose-connections. Then use compressed-air to blow out the residual fluid. (I like using leaf-blower for this task) Do not forget to blow the residue out of the heater-core.

Then, after you have removed as much residue as you can... re-assemble and fill with DISTILLED water. Feel free to drive with the distilled water in the system for awhile. This will help dillute whatever is left in the system.

Then, repeat the drain and blowout of the distilled water and reassemble again.

Upon occasion, I had to fill and run with distilled water several times before it drained out clear and clean. It is IMPERITIVE you get clear distilled water out of the system which indicates you have removed the residue.

ONLY AT THAT POINT can you add the proper antifreeze to the system. With any luck, you will end up with a system filled with pure antifreeze.

Do not forget to remove and wash out the overflow tank. I often toss a handful of small gravel inside the thing with some water and dish-detergent. The abrasive action of the gravel when shaken will make the tank clean....then rinse with clear water.

Hopefully, at this point, you will realize it is FARRRR easier to simply keep a supply of the PROPER antifreeze on-hand so you never EVER mix things up again.

 

[stocker]

If green is compatible with the blue, why replace it again? Seems like a waste of resources.

 

[brucep]

If green is compatible with the blue, why replace it again? Seems like a waste of resources.

Your use of the word "compatible" is misleading. Yes, the 'green' can be mixed with 'blue' .... but the result is not a desirable mixture for long-term use within your engine.

Personally, when I put a new radiator in my 2006 Baja (originally with green)...I switched it to Asian blue so all my vehicles use the same antifreeze.

In this way, I only have to keep a supply of Asian Blue on hand and it will work in both of my vehicles. My many years of maintaining vehicles has taught me to simplify as much as possible. (Same oil, same powerSteering fluid, same oil-filters..... etc)

 

[AWDFTW]

No need to dump it, just adjust down your service interval accordingly.

 

[dat2109]

Assuming you used one of the generic green (/gold) like prestone that is most easily identified by having a longer life rating around 100000 miles you really are fine, and I wouldnt worry about dumping it out in a hurry. Its different than the subaru stuff but gets along okay.

Here is a handy chart that shows some of the aftermarket products available.
https://images.oreillyauto.com/uploads/pdf/ad/SD_672%20AFZ%20Comparison%20Chart-1.pdf

 

[stocker]

Your use of the word "compatible" is misleading. Yes, the 'green' can be mixed with 'blue' .... but the result is not a desirable mixture for long-term use within your engine.

Personally, when I put a new radiator in my 2006 Baja (originally with green)...I switched it to Asian blue so all my vehicles use the same antifreeze.

In this way, I only have to keep a supply of Asian Blue on hand and it will work in both of my vehicles. My many years of maintaining vehicles has taught me to simplify as much as possible. (Same oil, same powerSteering fluid, same oil-filters..... etc)

That fair and I like your efforts to simplify. Probably less waste and half filled bottles around your garage too. I know with DexCool in my previous GM vehicle, if you mixed green with it, it would turn to sludge and you could really mess up your coolant system.

If you're fine with the extra effort, go for it. I was just pointing out that if it "works" for now, you could just change your service interval as noted below.

No need to dump it, just adjust down your service interval accordingly.

Assuming you used one of the generic green (/gold) like prestone that is most easily identified by having a longer life rating around 100000 miles you really are fine, and I wouldnt worry about dumping it out in a hurry. Its different than the subaru stuff but gets along okay.

Here is a handy chart that shows some of the aftermarket products available.
https://images.oreillyauto.com/uploads/pdf/ad/SD_672 AFZ Comparison Chart-1.pdf