Best coolant for 02 thru 04 Subaru boxer motors?

[Tremo]

Guys, what's the story? Subaru factory calls for "phosphate" based coolant. Supposed to work good on aluminum blocks and heads for corrosion prevention. Then I read that OAT coolants are best for aluminum motors.

What's the bottom line? Brands? Thanks.

 

[ZGRider]

Xerex for Asian cars. It's a "phosphated" OAT coolant. That's the same as the factory coolant.

 

[Tremo]

Any particular flavor of the Zerex?

 

[gj]

I have a 05' Forester.I checked with local dealer.Subaru's coolant is almost $18 a gallon.$2.50 for the additive.Unbelievable

 

[Ed_T]

I just pd that for 1 gallon pre-mixed Toyota Super Long Life.

 

[rcy]

Originally Posted By: Tremo
Any particular flavor of the Zerex?


http://www.valvoline.com/products/brands/zerex/antifreeze/105

Or you could bite the bullet and get the Subaru coolant as recommended at endwrench.com

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

I think Subaru still remommends the Cooling System Conditioner (see endwrench article), which appears to just be some sort of stop leak. Maybe they should just engineer a system that doesn't leak??!!

 

[Al]

Originally Posted By: rcy

. Maybe they should just engineer a system that doesn't leak??!!


Its actually just Subaru of America that recommends the stuff. Frankly I don't mind using it as any engine can spring a HG leak. Seems to be a good preventative.

I personally use the Subaru Coolant.

I have a Subaru Credit card. Its great for stuff like this...500 bucks a year (3% on all purchases)

 

[Tremo]

My local Subaru mechanic tells me the Subaru conditioner is mostly stop-leak because of the head gasket problems. He also says it can clog the heater core and radiator. Needless to say he does not recommend it, and he says even the mechanics that work at the local Subaru dealers don't recommend it.

No way in [censored] am I going to bend over and grab my ankles for dealer ripoff prices like 18 bux a gallion, gimmie a break.

I notice a lot of Subaru drivers are hardcore OEM-factory-dealer supplies and parts only. If they want to spend the bux, so be it. I prefer to spend my money more wisely and get aftermarket stuff that meets all the specs and works just as good.

I also read on a Subaru board that Peak Global meets all the Subaru requirements. so now we have two? Peak and Zerex?

 

[rcy]

You spent thousands of dollars on a new or used Subaru and now you're balking at $18 for Subaru coolant. Yes, it's more expensive than some aftermarket coolant, but at least you know it meets all Subaru requirments.

 

[Al]

Originally Posted By: rcy
You spent thousands of dollars on a new or used Subaru and now you're balking at $18 for Subaru coolant. Yes, it's more expensive than some aftermarket coolant, but at least you know it meets all Subaru requirments.

Ya' read my mind.

 

[Button]

Quote:
You spent thousands of dollars on a new or used Subaru and now you're balking at $18 for Subaru coolant. Yes, it's more expensive than some aftermarket coolant, but at least you know it meets all Subarurequirments.


Well the overprice Subaru Coolant & conditioner isn't working because people are still experiencing HG Failure(s).

 

[Tremo]

Originally Posted By: Button
Quote:
You spent thousands of dollars on a new or used Subaru and now you're balking at $18 for Subaru coolant. Yes, it's more expensive than some aftermarket coolant, but at least you know it meets all Subarurequirments.


Well the overprice Subaru Coolant & conditioner isn't working because people are still experiencing HG Failure(s).


Exactly.

The Zerex Asian coolant specifically says it meets Subaru requirements. Good enough.

 

[rcy]

That a problem with the headgaskets. Coolant has nothing to do with it. I was under the impressioin that the bad headgasket problem on the H4 were solved by about 2002 or so?

When I had my Outback, I didn't even use the conditioner, but then I had the H6 which doesn't have the headgasket problems.

Did you read the endwrench article?

 

[djb]

From what I've read, the most severe problems were with the head gasket design before 2002, but even 2002+ engines were prone to external head gasket leaks.

Note that this problem is coolant leaking external to the block, not between coolant and oil passages or combustion chamber leaks. The head gasket loses it seal at the edge due to combination of thermal expansion cycles and locally weak clamping pressure.

It does appear that the official Subaru assertion is that the head gasket leaks are *caused* by not using their coolant and additive. Not that their additive is a stop-leak that clogs the leak path caused by their badly designed head and head gaskets.

 

[djb]

Originally Posted By: rcy

Did you read the endwrench article?


That article was a completely a marketing piece from Subaru. I can summarize it as "use only genuine Subaru products in your Subaru".

It says that you have to use the additive, but it doesn't explain why. It doesn't admit that any non-Subaru products meet the required specifications, or even hint what those specifications are. "Formulated especially for the aluminum parts in your Subaru engine" is not a specification.

 

[rcy]

The only specifics it mentions are "It’s a phosphate (non-amine) type". But whatever, it's your car, run whatever coolant you want. The vehicle is out of warranty so what does it matter?

If it's going to keep you up night wondering if 'X' aftermarket coolant is OK in your cooling system, then just use the Subaru coolant.

 

[Drew99GT]

The Zerex Asian formula is similar to most all Japanese OEM coolants - silicate free phosphated hybrid organic acid technology. Napa carries it for $11 a gallon.

I believe the Subaru stop leak stuff is very similar to Bars leaks.

 

[Thingfish]

The Subaru conditioner is " Holts Radweld ".

 

[rcy]

Good catch. I didn't even notice the 'Holts' on the Subaru bottle.

 

[pbm]

I'd use Barsleaks tablets and Peak Global coolant if I had one of these 'leaky' engines.