Reddit reviews Subaru SOA635071 OEM Coolant System Conditioner

Fascinating. I'm wondering if Subaru recommends and approves only one type of "stop leak", something they call a coolant conditioner, such as this, https://www.amazon.com/Subaru-SOA635071-Coolant-System-Conditioner/dp/B00IGZP2UE

If you don't have record of the last time the coolant was changed, change it. To play it safe I'd use Subaru Super Coolant (blue) with Subaru Cooling System Conditioner (Holts Radweld).

In the event you need to do the head gasket, Speed Academy has an amazing video I used to do mine.

• Subarus tend to be easy to fix when they break. I have an '09 2.5i SE 5MT and I didn't even have to remove the hood to remove my engine.
  
• Make sure whatever brand you use the new gaskets are MLS (multi-layer steel). As they are regarded in the community I used Six-Star Bernie.
  
• If I had to do it again I would have used ARP studs to fasten my heads to the block.
  
• Machine shop labor is cheap. Take your heads to one to have them professionally-decked.
  
• When torquing the head studs into the block, find the Subaru directions (i.e., Mitchell1) and *follow them to the letter*. You're going to be turning them, backing them off, turning them again and whatnot. Just go with it.
  
• "As long as ya got it outta there" you can change these things as well:
  
  • Timing belt & pulleys, thermostat, water pump (Aisin / "eye-shin" sells a reasonably-priced kit)
    
  • Coolant hoses
    
  • Spark plugs
    
  • Engine oil and filter
    
  • Oil pump
    
  • STi engine mounts (left, right)
    
  • *RECOMMENDED* oil pickup (the OEM one tends to crack, starving your engine of oil)
    
  • *RECOMMENDED* timing belt guide (as the stamped OEM one failed when my engine blew, I replaced it with a Tomei milled one)
    
    Call me crazy, but when I blew my engine I elected to keep the car. Subaru has engineered a family sedan way better than it has to be for the market and it shows.
    
    I need to do some digging to find the invoices of parts I purchased; I'll update this reply as I find them.

Nice! As preventative maintenance Subaru sells this stuff. It is rebranded Holt's Radweld. Small bottle. I threw some in my daughter's Subie just in case. Can't hurt I guess. If the headgaskets on the replacement motor were original units then it is probably just a matter of time before they go too. But, you never know. This magic Subie juice is supposed to help.

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https://www.amazon.com/Subaru-SOA635071-Coolant-System-Conditioner/dp/B00IGZP2UE/ref=sr_1_3?crid=3GZ6ZTJOIDK4X&keywords=subaru+radiator+conditioner&qid=1554864612&s=gateway&sprefix=subaru+radiator+%2Caps%2C328&sr=8-3

You're getting ripped off at $2000, so $3,000 is astronomical.

My local subaru shop "not a dealer" does HG replacements starting at $900. There are often a few extra parts needed, so it can go up to $1,300, but that isn't often. They do great work and specialize in Subaru... I'm sure there is a similar shop in your area

With a new HG and some Subaru Coolant System Conditioner it should run 200,000 MORE miles.

Honestly, if you picked up a Subie with 78K for less than $3k, boy did you score... It's totally worth the REASONABLE HG replacement.

Not low on coolant √ So that sounds promising. I already have a new thermostat and will replace tomorrow. I just didnt want to drain the whole system again. Is the Subaru Coolant Conditioner something I should add as well?

Will check on the heater core hoses and update.

Thanks so much for your help!

http://www.amazon.com/Subaru-SOA635071-Coolant-System-Conditioner/dp/B00IGZP2UE

Do you have a small leak anywhere, and was the water pump changed the last time the timing belt was done? As others have mentioned the thermostat is a good place to start. Also Subaru makes a coolant conditioner that should be used when not using genuine Subaru coolant. It's a small bottle that can easily be found on Amazon here: https://www.amazon.com/Subaru-SOA635071-Coolant-System-Conditioner/dp/B00IGZP2UE

Did you change out your coolant with Subaru coolant and put in the Subaru coolant conditioner after your head gasket job? The conditioner is very important.

Example:
http://www.amazon.com/Subaru-SOA635071-Coolant-System-Conditioner/dp/B00IGZP2UE