Coolant change requiring conditioner?

A few months ago I replaced the coolant in my '00 OBW with 178K miles. Subsequently had to replace the lower hose but just reused the existing coolant mixture. Now I read below that Carl (1 Lucky Texan) states to re-add the coolant conditioner when new coolant is used. Is this needed after the original dose so many years/miles ago?

-- John

Reply to
John
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Do you know what the "conditioner" does? It's to plug tiny leaks due to warpage in the manifold-head gasket. It's the same reason you use non-Subaru "conditioners", like Bar's Leaks Head Gasket Repair. This is like filling your car tire with sealant goop for a [small] puncture rather than getting it correctly repaired. On old cars, these additives fix "leaks" elsewhere, too, like heater cores. Deposits build up in radiators (engine, heater) so there can be restricted pathways where these additives will then deposit and plug up. It might work as a temporary solution, possibly later result in plugs you don't want, has to be done with fresh coolant (and preferrably after a *good* flush job), and is really a crap shoot if it solves the problem at all.

Subaru contends that their "conditioner" is all that is needed to fix the leaks (while not admitting to the problem's actual cause). Well, the other leak plug additives claim to do the same thing. Subaru has never admitted the problem with their head gasket, their conditioner does not necessarily fix any existing leak, it may not fix any future leaks, and the use of their conditioner does not extend a warranty against head gasket leaks. A true fix is to replace the head gasket but obviously Subaru doesn't want to incur that expense in a recall, so they came up with the "conditioner" solution which isn't a good solution. A slow tiny leak may not have enough flow to get enough of the additive to plug the hole, a large leak won't plug, so only some leaks may get plugged. A new head gasket is the real solution but more pricey.

For phase 1 engines, the leakage is internal hence destructive. Hydrocarbons show up in the coolant (detectable only with specialized equipment) and may appear as sludge in the overflow tank. Bubbles are seen in the coolant immediately after starting the car. Overheating can be erratic but most often experienced on slowing down or stopping after running the car at highway speeds for awhile. Owners have thrown lots of money at trying to resolve various symptoms, like replacing thermostats, coolant flushes, new water pumps or radiators. If overheating occurs too often or is severe, head warpage occurs and requires engine replacement.

Whether you have the destructive internal leak or non-critical external leak depends if you have a phase 1 or 2 engine.

Phase 1: dual overhead cam

96-99 Legacy Outback or GT 98 Forester or Impreza RS

Phase 2: single overhead cam

2000+ non-turbo Legacy & Outback 00-04 Legacy GT 1999+ Forester or Impreza 2.5

It looks like you have a phase 2 engine. That means you don't need the coolant additive since the leak, if present, will be external. It does mean (without the additive) you may get a mess outside on the engine, not destructively inside the engine. You'd smell the sweet coolant that's on the engine, there'd be wet spots on the engine or on the floor, and the coolant level will slowly drop. If it were a phase 1 engine, a proper fix with a head gasket replace rather than use a coolant leak plug additive would cost ~$200 for do-it-yourself, $1500 at a good independent car shop, or $2000+ at a Subaru dealer.

If it's not a phase 1 engine, I'd say don't bother with the additive and live with any external leak mess, if any. The sweet odor of coolant heating up on the engine might become overly nuisancesome, though, but don't bother with the additive until that becomes a problem as it plugs tiny holes - around the head gasket as well as in the radiator and heater core. Some shops are pretty good at doing an acid bath of the radiator and heater core when they get plugged but it's a gamble (you might have to buy a new one). The flow rate through my old radiator (different brand car) was pretty low, I gambled on an acid flush, and

*wow* what a difference in flow rate and lower temperature. The flush is cheaper than new parts but solder repairs or replacement is expensive if the acid punches through. Other than flow rate, I'm not sure how a shop could determine the health of your radiator since they can only see the top of the fins when the coolant level is lowered to check the amount of deposits.
Reply to
VanguardLH

Thank you for the info. I have a 2000 Forester with a leak and it's reassuring to hear that I'm not doomed right now. It apparently is a phase

2 with an external leak and hasn't even run hot but one time when the coolant had gotten too low. I keep check on the levels now and everything seems fine except for that terrible burnt coolant smell :) Hopefully I can correctly repair it in the near future.
Reply to
Tim Conway

With "composite" head gaskets a "conditioner" CAN actually PREVENT a leak, rather than plug it - and an aftermarket "stop leak" cannot do that.

I don't know for sure about the Subaru product, but if it "conditions" the composite gasket material, keaping it from hardening and breaking down, it could be a good thing - and re-using the "conditioned" coolant would NOT require adding more when you put it back in.

Upon further investigation I find it is actually "holts radweld" - an extremely good and SAFE radiator/coolant system leak stopper. If the cooling system is full of coolant it CAN NOT PLUG UP THE SYSTEM. It disolves in the coolant and remains a liquid untill it is exposed to air and high temperature. When it seaps through a small leak and is exposed to air (oxygen, I believe, is required) it sets up forming a very reliable seal. Combustion gasses getting into the coolant will NOT set it up.

Never heard of Holt's Radweld or any other premium sealer plugging or damaging radiators, heater cores, heater valves, or any other engine/cooling system part.

I've used Knights alumaseal as well - different product - and never had a problem. I've used SolderSeal and BarsLeaks as well - not as impressed with them - as well as stop-leak cubes - which have never caused me a problem.

Been a mechanic since 1969 - licenced in 1971

Reply to
clare

And putting in the "conditioner" will NOT cause you a problem, now or in the future.

Reply to
clare

So you're claiming the conditioner makes the viton or whatever rubber- like material, if any, in the gasket get spongy and expand to fill the gap? If that were true, it means the solution is attacking and damaging the membrane which is detrimental to its function and lifespan.

The leaking can start immediately. No hardening or breaking after extended use is required for a leak to start.

Also, where did you see "Subaru Cooling System Conditioner" (part number SOA 635071) is actually a rebranded version of Holts Radweld? I suspect the Holts product has the extra stuff (detergents and rust converter; i.e., corrosion inhibitors) and the Subaru conditioner just has the surfactant. I haven't found an MSDS that is *specifically* for the SOA

635071 product. The only Subaru-sourced info that I've found on how their product works (which is really just jibberish) was:

Subaru "Endwrench" - Cooling System Conditioner Whenever the coolant is changed, you must add Genuine Subaru Cooling System Conditioner, (P/N SOA635071). It¢s been tested and approved for Subaru aluminum engines and radiators. Do not use aftermarket coolant reinforcement agents, sealers and/or flushing agents as those chemicals could corrode aluminum parts, or cause clogging. Genuine Subaru Cooling System Conditioner improves the efficiency of the cooling system and includes anticorrosive properties. When used as directed, it remains suspended in the radiator until the engine is started and thermostat fully opens. Once the conditioner begins to circulate throughout the cooling system, it is attracted to any suspected leakage area in the vehicle¢s cooling system. The heat generated by the engine acts as an activation agent and hardens the cooling system conditioner to help seal the area. Subaru of America, Inc. has determined that this product is safe for use in all Subaru vehicles."

"Improves efficiency". That's the surfactant. "Anticorrosive properties". That's the detergent and rust converter. "Attracted to any suspected leakage area". Oh yeah, like now the chemicals are a court dealing with suspects instead of acting on an existing physical condition. What their statement does indicate is the heat from combustion will solidify the conditioner to seal the leak on the combustion side of the gasket. Okay, but solidify WHAT? Nothing in the Holts product will solidify when heated. That's what makes me think their "conditioner" is actually a coagulate formulation like Bar's Leak which will transform into a Bakelite material when burned after leaking into the hot combustion side of the gasket.

Which would be true in the overflow tank for the radiator where there is air. What you describe is how Bar's Leak works: when exposed to air, the molecule increases in size and coagulates to form a plug. The Holts product doesn't work that way at all as it is a conditioner.

Sometimes I confuse the coagulate and the enhancer/booster products since "conditioner" is a generic term. The two types work differently. The coagulate product plugs a leak hence they can plug restricted flow paths through the radiator and heater core as well as for head gaskets. Conditioners don't stop leaks at all. Those are enhancers, coolant boosters, or pre-flushing products.

Conditioners aka coolant enhancers increase the surfactant action of the coolant to allow better contact between the coolant and a surface (engine surface). This aids in better exchange of heat and may reduce the temperature a few degrees. Notice in the MSDS (below) for the Holts product that its main component is the surfactant. The detergent and rust converter are to boost those already in the coolant.

Then what's the point of using the "conditioner"? An internal leak would be from WHERE to WHERE? And just what are combustion gases made up of (and where do they come from and what are they made of BEFORE the combustion)? I'm pretty sure even modern gasoline engines are still sucking in air to burn with the fuel. You're inconsistent. Air elsewhere makes the product plug a leak but air inside the combustion chamber is somehow different?

Holts Radweld MSDS

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disodium tetraborate (aka borax) - detergent

Reply to
VanguardLH

On Jan 20, 8:22=A0am, John wrote:

from cars101.com

******Certain 1999 through 2002 2.5L equipped vehicles may experience an external coolant leak at the head gaskets. As a precautionary measure, SOA is adding a special conditioner to the engine cooling system. This conditioner prevents leaks from occurring and corrects existing leaks. Only early Phase II 2.5 liter engines are affected. Phase I 2.5 liter engines (some 1999 model year and prior years) are not affected. Countermeasures applied to the manufacturing process for those 2002 and later VINS not affected by this campaign have eliminated the need for this campaign to be performed on those vehicles. In the future, it will be necessary to add Genuine Subaru Cooling System Conditioner to the SUBARU vehicle cooling system whenever the engine coolant is replaced. If the vehicle owner has this repair performed promptly, Subaru will extend warranty coverage on cylinder head gasket external coolant leaks to a period of 8 years or 100,000 miles, whichever occurs first. Warranty coverage begins on the date the vehicle was delivered to the first retail purchaser or on the date the vehicle was first placed in demo or rental service. The owner must have Genuine Subaru Cooling System Conditioner added to the vehicle at any subsequent cooling system services at the interval specified in the Warranty and Maintenance Booklet under the heading =93Schedule of Inspection and Maintenance Services=94. Resulting damage caused by a lack of maintenance or low coolant level will not be covered. ******

NOTE this sentence; "... add Genuine Subaru Cooling System Conditioner to the SUBARU vehicle cooling system whenever the engine coolant is replaced. "

Reply to
1 Lucky Texan

OK - my replies are >

Have you looked at the container??????? See:

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It says "holts" - stamped right into the plastic at the bottom of the blue bottle.

Says right on the bottle - so there is NO GUESSWORK INVOLVED.

It contains "proprietary resin solution", "borax Decahydrate" and "linseed meal". Says so right on the bottle. Don't believe me? Look at:

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The Borax Decahydrate is a cleaner. It conditions the cooling system and helps heat transfer.. It is used a a felding flux because it disolves and removes oxides. It is also an effective corrosion inhibitor. It buffers the acids produced by the breakdown of ethelene glycol, It is used in place of chromates in heavy deisel engine coolant. It is also an effective bonding agent used in starch adhesives, and in refractory cements. It is also a catalyst for organic driers, used in resin formulations (such as paint - and sealers???? It also acts to help crosslink hydroxyl groups. The "proprietary resin solution" makes a thin coating that finds it's way into small pores and openings in gasket materials where it seals porousity, and it also coats the inside of small cracks, where it sets up with heat. The Borax Decahydrate helps activate the resin

"linseed meal" also has interesting applications and characteristics. Linseed oil is used for making resins. It is an "organic drier" - which you may recall can be catalysed by borax decahydrate. It was also the basis for the resins in Linoleum flooring.. The fiber from the flax plant (source of Linseed oil and linseed meal) is the basis of LINen cloth. The fibers are also part of the fiber base of LINoleum.

I think it is VERY safe for me to state that Subaru Coolant Conditioner IS made by Holts - and it IS both a "conditioner" and a sealer, which has effective components/ingredients for both jobs. The claims Subaru makes for the product all make sense for the ingredient list - and the chance of it plugging up things that should not be plugged are EXTREMELY RARE.

YOU obviously do not know how it works.

Again, you do not have any clue how the "conditioner" works. Or the "sealer"

You are looking at the wrong Holt's product. They make about 200??? I may have been wrong about it being radweld. Mabee it's radweld plus. Mabee it is something different - but it IS a Holt's product.

And I showed you the ingredients list.

I said combustion gasses in the coolant will noit set it up in the coolant. I didn't say it would not set up in the crack.

Read the rest of what I just wrote.

The Holts product is not designed to fix fractured blocks. It is designed to seal seaping gaskets and plug MINOT LEAKS. It is NOT BARSLEAK. And it is not the same as Knights Alumaseal either. Those products are SEALERS or "Stop LEAK" - not conditioners - although they will have some "conditioning" properties

Reply to
clare

Nope. Never had to use it. There are lots of Subaru parts that I don't use. I'll take your word that its says Holts on the can. According to the following image link, it says "Manufactured in England for Subaru of America, Inc". The "Holts" is embossed in the plastic container. See:

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Again, never had to use the stuff so I don't have any of the bottles sitting around.

After your comments, I happened upon a pic of the actual product (not just the container) at:

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I see the links you gave were at the same site. I got the same site because you mentioned "linseed meal" which I could add in a Google search. As I said, I have yet to find an official MSDS (Materials Safety Data Sheet) that lists the ingredients of the Subaru Cooling System Conditioner product (and, no, I didn't have a bottle to look at but then many auto products consider their formulation a secret and don't disclose the ingredients). The MSDS for the Holts Redweld product can't be used to disclose what's in the Subaru conditioner since per your statement and some other sources found after my reply the ingredients of these two Holts products are different.

Which differs from what the MSDS says is in the Holts Radweld product. Might be Holts that makes the product but it doesn't look like the same product as their Radweld product that YOU mentioned.

So what we have is back to the heat/air activated coagulate type of "conditioner" - as per your own comments (not quoted here in my reply). Different products use different schemes to plug a leak but their effect is the same: pile up some blocking material to plug the leak. Hopefully the Holts stuff isn't just air-activated but also high-heat activated.

Reply to
VanguardLH

hmmmmm, linseed meal isn't listed on the MSDS I found(perhaps it is a carrier and not considered an active ingredient???), but it also is very light on info in general so, dunno what to think;

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from;

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Reply to
1 Lucky Texan

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Looks like the holts antirust isn't the ony thing sold as Subarucooling system conditioner, because what IS written on the bottle andthat MSDS don't even appear to be from the same planet. There IS a strong possibility that it is a product made BY Holt's FOR Subaru that is not marketed as a Holt's product..

All I know is what is printed on the container - which I reported - and what I THINK the mechanism behind it is, from my understanding of the ingredients shown onthe label.

All pretty benign stuff, really.

Reply to
clare

The sweeping statement about the double overhead cam engines leaking internally only and single cam engines leaking externally only is incorrect. Our '99 Fartster ( sohc) developed both internal and external head gasket leaks at approx. 85,000 km. Due to the dealership fobbing me off for two months when I tried to convince them the gaskets were leaking, leakage got to the stage where it disolved the coatings on the pistons and caused an unholy rattle. After much buggering about and totally inane excuse-making the dealership did the gasket job, leaving the pistons sounding like they were fighting their way out of the bores. A more competent and sympathetic dealership 120 miles from home finally got a Subaru Canada rep to examine the car. After about 30 seconds of listening to the engine he agreed it was pooched and authorized the installation of a complete new shortblock.

Sadly, the car sprung yet another gasket leak within less than a year. This time I had it done at a small independent garage for roughly half the cost of a dealership job, using aftermarket rather than Subaru gaskets. Hasn't leaked since.

Mine is not the only sohc engine to encounter the same internal gasket leak.

KH

Reply to
Kevin Hall

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