Unfortunately, misinformation abounds.... These guys are typically good with a wrench, but chemistry and electricity isn't their strong suit.

But I once again defer to the Factory Shop Manual. Until I see a retraction in the form of a TSB issued by SOA, this is the official final word....

 

I was at my dealer today getting the 7th of my 9 free oil changes, and went to the parts counter to pick up a quart of the concentrate. They have it on their web site but I figured I'd grab it in person. #SOA868V9260: Super Coolant Concentrate. 1 Quart Bottle

Well, not only don't they actually have any in stock, they don't show any availability within the district, so can't even order it for me.... But they did have plenty of Conditioner in stock, so I bought a bottle for $1.92 just to grab it while it's available.

 

Wow, only $1.92 per bottle? That is a very good price

 

Oops, looks like I fibbed.... I actually paid $1.93 (not $1.92 as reported!).

 

I just bought two bottles last week. It's always been in stock when I've needed it.

 

The coolant conditioner is still recommended, even with the updated MLS gaskets on this car. And, as many others have probably said, I'm pretty sure it's just rebranded "blue devil" stop leak. Though I don't know of anyone who has tried to use their own engine to test that theory yet.

 

And, as many others have probably said, I'm pretty sure it's just rebranded "blue devil" stop leak.

source? for a huge 32oz nasty jug clogging "blue devil",...

or simply a 4.4 oz bottle of thin holts rad weld. (which is kind of a misnomer as the stuff is really thin ). and says "holts" molded right on the plastic bottle.

 

The main ingredient in Radweld & Subi CSC is sodium tetraborate decahydrate (Borax). There are several theories as to why it work (as a buffer to raise PH - discussed by cooling system expert John Evans) or as a dehydrated glassy crystal that forms when a small amount makes its way into the fibers of the damaged head gasket in the presence of high heat. Either way, it seems to do the job.

 

Ah that looks more like it. My source was posts over the years at NASIOC which is not the best source for facts. Apologies.

 

Anyone use the ZEREX Asian coolant and the ZEREX Super Sealer instead of the Subaru brand sealer & coolant?

 

I should have added, I have a 2012 2.5L Outback with 58,000 miles and no coolant problems. I would like to keep it that way.

 

My 2010 Outback has 99K on it and I've never had any major issues with it; the car is taken to the dealer regularly and has all maintenance done there. I was driving home recently the thermostat light would come on and then go off. I drove about 10 miles to the dealership so they could check it out. Apparently the cooling fan crapped out, the coolant was just about gone and I had to get a new cooling system and have head gaskets replaced. Since they had the dang thing all apart, they replaced the timing belt. According to the service department, I now have a practically new car and should get a few hundred thousand miles on the car.

A week later, on the hottest day of the year, I start the car and no a/c, radio or clock, so I drive it to dealer. Mechanic comes to check it out and everything is working when it starts! They checked for fuse and loose wires, but everything looked good. I'm beginning to think I have a problem car and debating whether to get rid of it or not. Thoughts?

 

I too am interested in the Zerex "Asian Blue" is a direct replacement for Super Subaru Blue or whatever you call it. I've read a few posts suggesting it is but didn't know if this was confirmed. Both are silicate and phosphate free but clearly there is more to coolant than these two chemicals. In my case, my 06 2.5i came with the green stuff from the factory, however, the Blue is supposedly backward's compatible. Is it preferential to use blue from a chemical composition standpoint? I'll be completely draining the fluids when I pull the motor to do the head gaskets so I figure now would be the ideal time to switch over if ever there was one.

Interestingly, when I called to confirm parts availability from a parts retailer attached to a Dealership (Subarugenuineparts.com), the parts tech told me that they never use the conditioner in any models and "none of my guys do either." His opinion was that it is possibly helpful to slow down the progression of a coolant leak but was not used as a preventative measure currently as many other forum members, service techs, and my service manual recommend. I intend to follow my manual's advice and put in a bottle regardless, but figured I'd pass along this tech's perspective.

Thanks in advance for your advice,
s

 

Coolant Conditioner Required

I had 2.5 L 4 six star head gaskets installed 50000 km ago - unnecessarily as the problem was actually a pressure switch leaking- big bummer!

They added coolant conditioner & now my heater core - passenger side is plugged - Seems others have seen this
I understand the conditioner is basically Stop Leak?
Are the current specs still "requiring conditioner" for the 4's ?
I propose leaving it out as the car is WAY past warranty at 199,000 km.
Need to do a timing belt etc so A/F at the same time

What success is likely in flushing the core?

(Update on page 4 if you are finding this thread some time after it has been posted)

2011 2.5L with about 89k on it. No issues, drives great, no warning lights, heat blows hot at idle, etc. No symptoms of a coolant issue.

We have another vehicle that I'm currently working through some coolant problems on, which prompted me to take a closer look at the Outback because I can't remember the last time I looked at the coolant. It's been a while, a year or two probably. I know, not smart, but it is what it is.

Coolant was barely visible in the reservoir. Started cold engine, coolant not visible in radiator. I topped up the radiator and then the reservoir to the "full" line with the only coolant I have on hand, a premix that states "safe for all engines American/Asian/Euro."

So, a few questions:

- Do I need the Subaru coolant?
- Do I need the conditioner?

The vehicle could probably benefit from a change and fill as I have not been paying it the attention it deserves, but I'd really like if it could wait until warmer temps here. So, is an off the shelf premix at proper levels okay to get me a few months down the line, or should I be making plans to drain and fill sooner?

Thanks for your help.

 

Yes, the service manual recommends the addition of Subaru Cooling System Conditioner, and there have been no TSB's that I'm aware of that countermand the instructions in that document.

Being that the main ingredient of SCSC is Borax which is totally soluble in hot water, I really reject that it caused a heater core clog. It's far more likely that somewhere in the vehicle's history somebody added an incompatible coolant, hard water or other additive, and that induced your current issue.

 

Automotive cooling systems these days have become very dependent upon running ONLY the specific coolant formula recommended by the manufacturer. If someone introduces the wrong coolant (or other chemicals) into a cooling system, gelling and eventual cooling system failure can easily result.

For this reason I would never add a "coolant conditioner" to the properly-spec'ed coolant, even if the manufacturer says to do so. Too many variables and therefore too much risk. But that's just me. Your mileage may vary.

 

Automotive cooling systems these days have become very dependent upon running ONLY the specific coolant formula recommended by the manufacturer. If someone introduces the wrong coolant (or other chemicals) into a cooling system, gelling and eventual cooling system failure can easily result.

For this reason I would never add a "coolant conditioner" to the properly-spec'ed coolant, even if the manufacturer says to do so. Too many variables and therefore too much risk. But that's just me. Your mileage may vary.

Is this not a bit of a contradiction? I agree that I don't add coolant additives, but what if they are specified in the owner's manual? You say that you use "only the specific coolant formula recommended by the manufacturer" but what if part of the formula is coolant conditioner as it is in this case? According to the multiple other threads on this topic, Subaru recommends the use of their coolant conditioner and no TSB has been issued to reject this instruction.


s

 

Owners manuals can be wrong. Consider the number of manufacturers back in the mid-2000s who specified in their owners manuals that their transmission fluid was "lifetime", never needing to be changed or refreshed during the life of the vehicle. We now know that that there has never been and will never be "lifetime" fluid of any type on any vehicle. Formulas break down with time and miles, contamination occurs, and the fluid chemistry (such as friction modifiers) loses its ability to protect over the long haul.

In the case of aging coolant, I would drain and fill with fresh coolant as opposed to adding conditioner.

As I stated, this is a choice I make for my own vehicles. Your choice for your vehicles may indeed be different.

 

Let me state this again, if I wasn't perfectly clear the first half dozen times. I have 3 service manuals at my disposal. 2010, 2013 & 2014. SUBARU FACTORY SERVICE MANUALS, not glove box Owners Manuals.

If the folks that build and warranty the engine say to use it, I'd strongly encourage you to listen!

Page CO(H4DO)-2 Cooling System General Description, bottom of the page:

Cooling system protective agent Cooling system conditioner SOA345001

And from a TSB: Whenever the coolant is changed, you must add Genuine Subaru Cooling System Conditioner.


Are we clear?

 

I find it interesting that we choose to selectively treat the recommendations in the owners manuals as gospel. We generally follow the owners manual recommendations except we don't believe the manual when it comes to lifetime CVT fluid or the specific oil viscosity recommendations. Myself included, I change the oil more frequently than the bible recommends and also changed the lifetime CVT fluid.

Yogi Berra would say the owners manual is always correct.... unless it is wrong

 

Just to add to this tread:

- Older mechanics will add Subaru Coolant Conditioner as a matter of fact. They are so used to doing it, they just do it as a matter of principle.

- Shops trying to cover their asses will also add Subaru Conditioner, as what it really is is a form of leak weld. For example, we had the short block replaced on our 2.5 FB, and the car started to use coolant. The dealer, being rocket scientists, told us our A/C issue was a freon issue, but the car was actually 3-4 liters low on coolant. In an attempt to cover the very small leak in the head gasket, they put in Subaru Coolant Conditioner. Yeah.... it didn't work. (Engine two is being installed now.).