coolant for '98 Subaru Forester

[foresthawk]

The owners manual says to use an "ethylene-glycol basis coolant."
Please recommend a coolant for this engine.
I am new to this car.(and this forum).
I also find the coolant selections in autoparts stores a bit confusing these days. Thanks for any suggestions.

 

[Rolf]

Originally Posted By: foresthawk
The owners manual says to use an "ethylene-glycol basis coolant."
Please recommend a coolant for this engine.
I am new to this car.(and this forum).


According to Subaru, (Service Bulletin 09-42-05, Date 4/15/05) their current replacement recommendation is Subaru Long Life Coolant, which contains phosphates and is amine-free.

That is, btw, pretty much what Toyota and Honda use.

On the Internet there's a fair amount of discussion of failed Subaru headgaskets due to the use of DexCool and its clones, like the Prestone and Peak "fits everything" coolants.

So, I'd exclude the Dexcool and "universal" coolants.

If you have access to OEM Toyota or Honda coolant, they'd work.

As far as stuff you'll find in most parts stores, a low silicate long-life green coolant like Zerex 5/100 would work. If you wanted to upgrade, the Mercedes/Ford/Chrysler G-05 coolant would also work and provide somewhat longer life. G-05 does not contain phosphates, but it contains an organic acid that does pretty much the same thing.

Be sure to double flush the system before you add whatever you wind up buying.

 

[JayhawkRoy]

Our Subarus used "standard" green, from the mechanic.

Those years, the Subaru owner's manual maintenance schedule called for 30K coolant change intervals, so "long-life" coolant is somewhat of a misnomer also, if you followed the maintenance schedule.

 

[rcy]

Try here.

http://endwrench.com/images/pdfs/WhatEWNov05.pdf

http://endwrench.com/images/pdfs/CoolantInsidEWMay05.pdf

Not suggesting your mechanic is wrong (though 'standard green' seems a bit vague), but the first article is for all Subaru's, regardless of year. Maybe back in '98 they did use 'standard green'.

I'm also not suggesting one should ONLY use Subaru brand coolant, but they do suggest a "phosphate, non-amine coolant formula", which I don't believe 'standard green' is.

 

[Rolf]

Originally Posted By: rcy
Try here.

http://endwrench.com/images/pdfs/WhatEWNov05.pdf

http://endwrench.com/images/pdfs/CoolantInsidEWMay05.pdf



Nice.

The "amine" refers to an additive used to prevent cavitation in diesels. It's not needed in spark ignition engines, but prevents a type of metal erosion in compression ignition engines.

If the formula is properly balanced, it shouldn't have any adverse effect on the Subaru.

The "reaction" mentioned in a mixed aluminum/ferrous system is electrolysis. Aluminum in hot water acts like zinc does at normal temperatures - it will sacrifice itself to protect ferrous components. The "phospates" coat the surfaces and basically insulate them electrically, preventing electrolysis.

The Japanese manufacturers prefer this approach, which works well with their soft water. However, if folks add typical US hard water to their systems instead of factory coolant and distilled water in the proper ratios, a white mineral buildup can occur and screw things up.

The approach used in G-05 is to use a very small amount of silicate and an organic acid, which coats the system and does what the phosphates do. It works great in aluminum/ferrous environments.

In the long life conventional green they leave out the organic acid and use conventional inhibitors.

Both are in the same ph range as the Subaru.

I would definitely avoid the DexCool and similar coolants.

 

[JayhawkRoy]

Unfortunately the first article looks like a paid justification for using only Subaru coolant. I will check out the ASTM spec next time I am at the parts store, and see what choices I may have.

Standard green is plenty vague, based on the owner's manual requirement for ethylene glycol, not special Subaru over-priced coolant; Subaru does not specify or require their coolant, due to Moss-Magnusson reasons, and "highly recommends" it.

My view is I shouldn't have to relearn chemistry to choose a maintenance item like coolant, and Subaru (who wasn't first with the concept) and the rest of the auto world who keep coming up with proprietary special products to keep up their profit margin will quickly lose my business. My cars never see dealerships after the warranty runs out and I am not going to make special trips for maintenance fluids.

Off the soap box -- thanks for the enlightenment.

 

[JayhawkRoy]

Here is what I found to be the most authoritative discussion on this subject. From http://www.legacygt.com's forum

"Subaru specifies a non-silicate, non-phosphate and non-amine antifreeze. They also refuse to tell anyone which brands meet their specifications.

By law, Subaru cannot mandate Subaru coolant unless they provided it for free.

I spoke with a chemical engineer at the company that manufactrurers Peak Coolant last week for 40 minutes. Here's what I found out:

Peak Global is 100% phosphate and silicate free.

Virtually ALL coolants manufactured for the past few DECADES are non-amine. Therefore, nobody lists non-amine on their coolant bottles.

The ingredients in Subaru and Peak Global are identical except for minor differences in the anti-corrosion package.

The company that makes the anti-corrosion package for Subaru coolant also supplies Peak. That company has told Peak Subaru's anti-corrosion package is 100% compatible with Peak's. they are virtually interchangable.

In a brilliant marketing move, Subaru has managed to skirt the Magnusson Moss Act but telling us to only use a "non-amine" coolant. Since nobody's made a non-amine coolant for years, we're running around looking for coolant that doesn't have something that isn't around anymore.

It's like your doctor telling you it's OK to drink cola, but make sure the label says cocaine-free. How long has it been since Coca-Cola's ingredients included cocaine?

By the way, the guys at Peak are very familiar with Subaru, Subaru coolant and Subaru coolant additive.

As far as I'm concerned, Peak Global Coolant is the equivalent of Subaru coolant."

This poster goes on to say that Peak Global meets the Subaru spec 100%, so that will be what I use next time.

 

[FZ1]

Just go to your dealer and get the proper coolant for you brand of car.

 

[Rolf]

Originally Posted By: JayhawkRoy
.... The ingredients in Subaru and Peak Global are identical except for minor differences in the anti-corrosion package. ....


That's not exactly correct.

All ethylene glycol coolants are identical except for the anti-corrosion package. Peak Global® LifeTime Antifreeze & Coolant is a DexCool clone:

"PEAK Global LifeTime Antifreeze & Coolant is a new coolant technology that can be used in all automobiles worldwide, regardless of make, model, year made or current antifreeze color. PEAK GLOBAL LifeTime Antifreeze & Coolant is based on patented organic acid technology (OAT) and uses patented advanced engine protecting inhibitors to provide maximum protection against damaging rust and corrosion in all automotive cooling systems. "

http://www.peakantifreeze.com/faq_global.html#A

That is definitely NOT what Subaru recommends.

The "amine" issue is not an issue - amines are added to provide protection in diesel engines.

Peak ALL WEATHER is laden with phosphates.

Peak Sierra is not ethylene glycol.

Do as you wish, but I'd either go with a long life green, one of which Peak makes.

 

[pbm]

Rolf: A few years back when I contacted PEAK I was told that their Global Lifetime A/F did not contain 2-EHA. This is the 'plasticizer' in Dexcool that supposedly causes gasket problems. I doubt PEAK would have added 2-EHA since I spoke to them.

 

[Rolf]

Originally Posted By: pbm
A few years back when I contacted PEAK I was told that their Global Lifetime A/F did not contain 2-EHA. This is the 'plasticizer' in Dexcool that supposedly causes gasket problems. I doubt PEAK would have added 2-EHA since I spoke to them.


Yes, many of the Japanese manufacturers eschew 2-EHA because it softens hoses and gaskets. I assume you're referring to PEAK's Global LifeTime product, and not one of their other coolants:

http://www.peakantifreeze.com/aboutus.html

However 2-EHA is not the reason I suggest not using PEAK's DexCool clone (PEAK uses another organic acid, sebacate I believe):

http://www.peakantifreeze.com/msds/msds_peak_global_lifetime.pdf

but the lack of any other inhibitor such as phosphate or silicate that would provide the "quick heal" protection that G-05 and the factory fills such as Toyota and Honda use. If you get air in the system, you'll find out why DexCool clones can turn brown in a hurry.

 

[Eddie]

G05 is a common use coolant for Subarus. I used G05 in my 2000 Forester for 127,000 miles without issues. I did a change every 36,000 miles and did a 50/50% solution using distilled water.