Subaru Cooling System Conditioner (P/N SOA635071)

Heads, valves, pistons, rods, crankshaft, etc...

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ciper
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Subaru Cooling System Conditioner (P/N SOA635071)

Post by ciper »

Anyone use it? Supposedly Subaru issued service manual/user manual updates for all vehicles stating it should be used.
vrg3
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Post by vrg3 »

I thought it was just for certain models. From what I've read, it's essentially a Stop-Leak type treatment.
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rallysam
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Post by rallysam »

I got one of these letters for my RS. Does anybody know what the deal is? Has anyone seen a thread on nasioc with info about this?

It sounds like SOA is saying that my car is prone to blown head gaskets.
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vrg3
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Post by vrg3 »

All non-turbo EJ25s seem to be a little more prone to blowing head gaskets than they ought to be.

There are some who suspect that the cooling system conditioner is a hack that's meant to postpone problems until after the warranty period expires.
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czo79
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Post by czo79 »

yeh...I'm wondering about this. I had headgaskets go in my 97 GT at 59k miles...It was such a bitch to get that covered under warranty. In my new 97 GT, I have an 01 rs engine, so its effected by this issue. I have also heard people saying that you should only use genuine subaru coolant (who makes it for them?) because other ones can cause problems with the headgaskets somehow...
I'm wondering if its a good idea to use the subaru coolant, whether I should be vigilant about regular flushing of the coolant system...and whether I should use that sketchy additive...
Hmmm.
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evolutionmovement
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Post by evolutionmovement »

I can't imagine how much of a difference coolant will make other than build up in the water jackets. Personally, I suspect the blown HG issues have to do with the open deck design and relatively large heavy pistons moving the cylinders around. A better gasket could probably last longer, but I think relatively prematurely blown HGs are inherent to the design.

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kyledooley
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Post by kyledooley »

The coolant conditioner is simply your garden variety stop-leak.

The problem is on Phase II EJ25s up to 2001 model year.

The head gaskets are prone to leak at the rear driver's side. There is a spot where they develop a leak between the lower side coolant passage and the outside. They don't breach the combustion seal.

The affected EJ25s will periodically lose coolant for no particular reason. Sometimes there is a coolant smell that doesn't seem to have a precise source.

Subaru has extended head gasket warranties on these cars to 8yrs/100,000 miles (IIRC).

There is no such thing as "Genuine" subaru coolant. Just use any old regular green stuff.

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Post by vrg3 »

I thought it was important that the coolant be phosphate free. Or maybe silicate free. Or both? I don't remember.

There is such a thing as genuine Subaru coolant. A quart is part number SOA635002 and a gallon is part number SOA868V9210. The question is just whether or not it's any different from other coolants you can buy for a third the price.
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