Subaru coolant conditioner... yes or no?

[mwiener2]

I've taken apart hundreds of Subaru motors. It's obvious if it had conditioner in it.

[DrD123]

I've taken apart hundreds of Subaru motors. It's obvious if it had conditioner in it.

Subaru is saying put it in every engine they sell when changing the coolant - literally every single solitary engine they sell. Even if it's a stop leak, nothing should happen until there it sees air+heat. What have you seen? obvious it's been in there means what? performance problem? coolant system gummed up? water pump failure? Folks generally have strong opinions both ways when it comes to additives - I was really hoping through this thread to get actual information, rather than just random opinions.

 

 

 

The post above is very interesting, and suggests that's why Subaru says to add it to the radiator rather than the overflow - in the overflow you have air+heat, so things will start crashing out if there are stop-leak sort of additives in there. That the coolant system was clean is also consistent with that. (of course, even adding it to the radiator, if it's well mixed in the system you'd expect some exchange into the overflow, so it will get gross, I am guessing!)

[nevets27]

It should be pretty easy to actually test if the two product are in fact the exact same. Do a specific gravity test and look at them through a refractometer. By no means a definitive test. If in both tests they show different results then its definitely not just a re-labeled product. Now that doesn't necessarily mean it doesn't serve the same purpose so it's not really proof of anything per say but it's closer to a real test vs anecdotal evidence.

 

If heat + air makes it gum up then maybe you could just boil it and see what it does. If it's not stop leak I would assume it shouldn't change.

 

The part I find a bit weird is why would subaru suggest it in all engines across so many years when the head gasket issue was pretty much isolated to the 2.5NA's? Seems a bit unnecessary and if it causes such issues for the coolant systems then subaru would have just been screwing up perfectly good engines that didn't need it in the first place. Then again car manufacturers do weird blanket stuff think that so I wouldn't be shocked they suggested/did something stupid.

 

Would be interesting to know how many cars out there are running with it. Assuming if all mechanics followed Subaru's recommendations, it would be the majority of Subaru's on the road. Of course that's unlikely the case. Possibly all dealership may have always used it though, that would be a reasonable portion of cars on the road.

 

I don't see it brought up here but it's possible it could be water pump lubricant. That's definitely a thing and it is an additive. Would it be necessary or not that another story but it should have no ill effects on the coolant system.

 

Or it could just be exactly what everyone thinks and it is in fact radweld.

[DrD123]

I was thinking just run the two samples side by side via ICP-MS without trying to run down what's what in the spectra, you would definitely see if the same things are in both, or if there are differences.

[Scubaboo]

I'd be curious what a complete lab workup would show if you guys were to really look into this, but it just seems less likely that Subaru has a special breakthrough conditioner that does things coolant cant, and more likely that speccing stopleak across the board will cut down or push out past warranty enough head hasket claims to be worth it.

[dgoodhue]

Subaru has a special breakthrough conditioner that does things coolant cant, and more likely that speccing stopleak across the board will cut down or push out past warranty enough head hasket claims to be worth it.

 

I highly doubt that its for warranty claims, Subaru doesn't recommend changing the coolant until 137,500 miles. If you consider 105,000 when the timing belt is and as coolant change intervals for EJ25's timing belts, it is still well past the 5/60K powertrain warranty

[Scubaboo]

I highly doubt that its for warranty claims, Subaru doesn't recommend changing the coolant until 137,500 miles. If you consider 105,000 when the timing belt is and as coolant change intervals for EJ25's timing belts, it is still well past the 5/60K powertrain warranty

 

Makes sense!

[busyychild]

Subaru doesn't recommend changing the coolant until 137,500 miles.

 

Coolant service on the early 2000s/Long Life Coolant (Green) models is 60K.

 

The 2008+/Super Coolant (Blue) models have the extended service time.

 

It's highly possible that the use of this cooling system conditioner was to mitigate head gasket failure on these these early and non turbo models without the MLS head gaskets. To reduce failure (and warranty claims) prior to end of warranty.

 

I haven't seen it stated anywhere that any Super Coolant Subaru models need the conditioner.

Edited June 16, 2021 by busyychild

[DrD123]

It's stated in all the Subaru factory service manuals for late model (post 2002) Subarus I have (through 2019 for the Legacy/Outback, through 2015 for the Impreza, through 2020 for the WRX/STi, through 2019 for the forester, through 2020 for the BRZ, and through 2014 for the Tribeca) all have add the conditioner as step 1 of the coolant refill procedure. Its definitely called out in the 11 Legacy owners manual (I haven't checked others - I just collect service manuals) - so it's definitely specified by subaru for cars which specify the super coolant.

[busyychild]

Interesting, I stand corrected. I had always read it had to do with the lack of a MLS gasket, and had assumed it’s exclusive use in all engines started when the Super Coolant became the standard.

 

 

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[mwiener2]

If the conditioner was so super critical, it would come from the factory with it in the cooling system.

 

It's a chemical band-aid to reduce warranty claims.

 

The change interval is 130+k miles. If you are changing it before then, there must be something wrong and add chemical band-aid to prevent a claim. Also, you've opened the system and introduced air. Since everyone is incompetent and can't burp the system properly, add chemical band-aid to prevent excessive corrosion, early failure, and a claim.

 

If you make it to 130+k miles, holy crap it's old, there could be a problem, add chemical band-aid.

 

 

The issues that the chemical can "fix" are not fixed properly. The conditioner only delays problems, and in many cases, causes problems by gunking up the cooling system.

 

 

I can guarantee that the dealerships are not adding conditioner every time they service a cooling system.

 

 

 

DO NOT USE THE CONDITIONER!

 

 

I used to see a lot of engines with conditioner in them up to around 2010 (The actual year, not model years of cars.) After that, I saw less and less.

Recently, I see a car with conditioner about once a year. Usually a EJ20 WRX that only had 1-3 owners. Usually blown up.

Edited June 22, 2021 by mwiener2

[Alexmed2002]

If the conditioner was so super critical, it would come from the factory with it in the cooling system.

 

This is how I see it too...

[DrD123]

If the conditioner was so super critical, it would come from the factory with it in the cooling system.

How do we know it doesn't?

Also, you've opened the system and introduced air. Since everyone is incompetent and can't burp the system properly, add chemical band-aid to prevent excessive corrosion, early failure, and a claim.

adding air wouldn't deplete a corrosion inhibitor, but air+heat (well, oxygen+heat) could get a leak preventing additive to start to agglomerate, but it would likely take more than just a little air+heat to do that. (in terms of bleeding, I've found the 5th gen to bleed very easily - filling, squeezing the upper/lower radiator hoses to push out bubbles, then close it up, fill the overflow, and the system will let out any residual air after a trip or two, then just fill the overflow bottle back up to full and you are good to go.

 

 

I used to see a lot of engines with conditioner in them up to around 2010 (The actual year, not model years of cars.) After that, I saw less and less.

Recently, I see a car with conditioner about once a year. Usually a EJ20 WRX that only had 1-3 owners. Usually blown up.

Blown up from the conditioner? If the conditioner were the issue and killing engines, one would think there would be a class action suit similar to the spun bearing one for the WRX/STi with the EJ25... if the conditioner were gumming things up, causing overheating, etc. it should be pretty straightforward to see that, then Subaru would be in a pretty tough position since they specify it for all of their engines...

[mwiener2]

We know it doesn't because new Subaru's don't have white shmegma gunking up their cooling system.

 

This is simple closed system technical stuff. There is oxygen present in the cooling system. The oxygen reacts with other stuff and oxidizes. Eventually, all the oxygen oxidizes and there is none left and the corrosion stops. If the system is opened or new coolant is added, new oxygen is present and the corrosion continues.

Our coolant system is not actually "closed" since it can breathe through the overflow bottle. But I wouldn't call it an open system either.

 

 

The conditioner did not blow up the engine directly, but decreased cooling system performance could contribute to a failure of the motor. Since the conditioner is a band-aid, it would never be blamed on a failure since there would be a more direct cause, like a blown headgasket. Determining the role of the conditioner on a hedgasket failure on a per car basis is almost impossible to prove.

 

 

When do I get a badge that says. "I've been doing this longer than you. I'm actually a professional. Please just listen to me.?"

[DrD123]

We know it doesn't because new Subaru's don't have white shmegma gunking up their cooling system.

as posted above, in a coolant system where someone added the conditioner, while there was some guck in the overflow, the coolant system was clean upon disassembly

This is simple closed system technical stuff. There is oxygen present in the cooling system. The oxygen reacts with other stuff and oxidizes. Eventually, all the oxygen oxidizes and there is none left and the corrosion stops. If the system is opened or new coolant is added, new oxygen is present and the corrosion continues.

so your argument is that aluminum doesn't corrode in water with a low dissolved oxygen content? that, I am afraid, is 100% incorrect. There are a number of other viable cathodic reactions that will support corrosion in a deaerated system (even in 100% pure, zero dissolved oxygen water, corrosion can go on aluminum - there are other metals where it can't - copper being one, but aluminum will corrode just fine). The oxygen introduced by an air bubble is going to be somewhat small (considering the size of the bubble, the number of things that will consume oxygen as it makes its way into the water, and the relatively slow transfer rate into the water)

The conditioner did not blow up the engine directly, but decreased cooling system performance could contribute to a failure of the motor.

was there decreased cooling system efficiency? seems unlikely you'd film the inside of the radiator - it would more likely collect at dead spaces/reduced flow regions, I would think - would be really cool to see actual data/images...

 

Since the conditioner is a band-aid, it would never be blamed on a failure since there would be a more direct cause, like a blown headgasket. Determining the role of the conditioner on a hedgasket failure on a per car basis is almost impossible to prove.

if the coolant system were all crapped up, and lots of folks with blown engines were seeing that, it would get attention - just like other pattern failures - and given how litigious our society is, there would eventually be some enterprising lawyers who put together a class action suit. It's called out as a requirement for literally every vehicle Subaru has sold for the past 20 years or more!

When do I get a badge that says. "I've been doing this longer than you. I'm actually a professional. Please just listen to me.?"

Seriously? I listen to data, which is what I was hoping would come out of this thread - I spoke about opinions earlier in the thread.

[RWebb]

Seriously? I listen to data, which is what I was hoping would come out of this thread - I spoke about opinions earlier in the thread.

Welcome to mwiener2

[dgoodhue]

I used to see a lot of engines with conditioner in them up to around 2010 (The actual year, not model years of cars.) After that, I saw less and less.

Recently, I see a car with conditioner about once a year. Usually a EJ20 WRX that only had 1-3 owners. Usually blown up.

 

Wait WHAT?! You are basing your claim of the conditioner making a mess of the coolant system on your experience of working on cars circa 2010. The blue coolant didn’t start until ~2009 and in 2010 you probably were dealing with the actual EJ motor with headgaskets issues.

[dgoodhue]

This is how I see it too...

 

You wouldn’t even crawl up under your car to see where the oil leak was and you want us to listen to your expertise?

[busyychild]

I like this game.

 

How I see it...

 

Facts:

- Subaru in most instances recommends the use of the conditioner irrespective of coolant type (Long Life/Super).

- Early model Subarus that did not have the MLS head gaskets were prone to head gasket failure.

 

Assumptions:

- The conditioner was used to address premature head gasket failure in models with non-MLS head gaskets.

- The conditioner has chemical components missing from both types of factory coolant that is required for the optimal operation of the cooling system and or head gaskets.

- Subaru manufactures their engines, head gaskets and or radiators with inherent flaws.

- The conditioner is Radweld/Stop-leak.

- Super coolant was introduced to reduce the service intervals and overall cost to the consumer.

 

 

It will take an analysis of the conditioner to move some of those assumptions into facts.

[nevets27]

I have been professionally working on Subarus for over 13 years.

 

Recently, I see a car with conditioner about once a year. Usually a EJ20 WRX that only had 1-3 owners. Usually blown up.

I assume you've seen a lot of blown up engines in general over 13 years. It begs the question, how many haven't had the conditioner (that you know of) but still blew up?

 

I highly doubt that its for warranty claims, Subaru doesn't recommend changing the coolant until 137,500 miles. If you consider 105,000 when the timing belt is and as coolant change intervals for EJ25's timing belts, it is still well past the 5/60K powertrain warranty

 

This is why I don't get the "subaru did this to protect themselves from warranty claims" argument. If it was to stop warranty claims it wouldn't have any effect if the coolant was changed per the service schedule which is well after the warranty had expired.

 

Why would they even care if you used it when you finally did your coolant change at 137,500 miles, if it was just a stop leak for head gaskets?

 

If it truly is a conditioner, then it's likely something that came in the system from the factory. Which means it's not being "added" later it was always in there.

 

Or, like the documentation says, (example) they realized there was a corrosion problem that would be an issue when the coolant system was getting older (at 137,000 miles) and now requires some additives for more corrosion protection. The manual actual mentions after the first 11 years or 137,500 miles that the coolant should be changed on a 6 year 75,000 mile interval for the rest of the life of the vehicle.

 

I'm contrast I have seen the WWP-99 service campaign but that was up to 2002. Though it does basically say that the subaru coolant conditioner is a stop leak.

 

I'm not aware of a service campaign/TSB/recall for 2002 or newer vehicles, does one exist?

 

It all seems a bit odd to me. If in 2002 they wanted it in all engines past, present and in the future, wouldn't they haven been adding it at the factory at that time? If not then the first time it gets introduced into the engine is 77,500 miles after the warranty has ended?

 

Logic/speculation can go on forever. I'm a bit surprised no one has actually tested it yet. Only real way to know.

Edited June 24, 2021 by nevets27

[Alexmed2002]

You wouldn’t even crawl up under your car to see where the oil leak was and you want us to listen to your expertise?

 

Never needed to. The oil was coming from the headgaskets. What does that have to do with this thread? That happened over a year ago. I never said I was an expert either, I just simply agreed with another user's perspective...

[Scubaboo]

[DrD123]

Well, since literally all of their products are in the same container, some of them blue, some black, etc., that tells you absolutely, positively nothing.

[DrD123]

If it truly is a conditioner, then it's likely something that came in the system from the factory. Which means it's not being "added" later it was always in there.

 

Or, like the documentation says, (example) they realized there was a corrosion problem that would be an issue when the coolant system was getting older (at 137,000 miles) and now requires some additives for more corrosion protection. The manual actual mentions after the first 11 years or 137,500 miles that the coolant should be changed on a 6 year 75,000 mile interval for the rest of the life of the vehicle.

For an aging system, it's not at all uncommon for corrosion inhibitor demand to increase, either due to corrosion initiation within the system that wasn't effectively suppressed by the original inhibitor package (in most closed systems, you monitor and add inhibitor as the system operates and the inhibitor is consumed or decomposes - obviously you can't do that in a car) - also, when doing a drain and fill, you never really get everything out, so there would be some residual stuff in there. Were it me, for a low maintenance system like a car cooling system, I would be inclined to make similar recommendations for a reduced time period.

 

Logic/speculation can go on forever. I'm a bit surprised no one has actually tested it yet. Only real way to know.

Exactly! It would be great to have either an analysis of the products or even empirical evidence showing damage to the system that can be conclusively demonstrated to be from the conditioner

[nevets27]

Case closed then. Everyone knows the shape of the container dictates what's inside. I'm sure most people have seen that so little chance this is news to anyone.