Is coolant conditioner still required

[LD111]

I have a 2005 Outback EJ253. I rebuilt the motor and flushed out the cooling system well. I used the OEM Subaru gasket kit for the turbo model including the head gaskets. I purchased 2 gallons of pre-mix blue super coolant from my local dealer. They said they don't have any conditioner listed to add. I don't think he had been around for very long and didn't even know what I was talking about. An older tech came to the parts dept so I asked him and he said that was BS warranty thing and as long as I flushed all the old coolant out, I was good with the blue coolant alone. The bottle even says required for all warranty repairs and no additional corrosion additive needed. If I am correct, the conditioner was a stop leak. I don't want to add junk to my engine. is this no longer recommended?

[golucky66]

There are still coolant conditioners. I use them at my shop anytime I do a coolant flush (comes with the kit BG gives us) I have asked a few older co-workers as well as our local representative from BG and they all agree that the conditioner is not needed, just another thing to add to the system as "insurance" to help it last longer. This additive that my shop uses is NOT stop leak. And I wouldn't recommend putting stop leak in it unless its actually leaking and as a temporary fix.

Moral of the story. Everyone I've asked says its not mission critical to add it, just "nice".

[LD111]

Thanks for the info.

[Fairtax4me]

The conditioner was a cover-up fix for the leaking head gasket problems Subaru had in the late 90s - mid 00s.

You've replaced the head gaskets, the newer gaskets designs cure the condition that caused them to leak, so conditioner is not required.

If you want to run it as a cheap insurance policy, you can, but if the conditioner has been added to the system in the past, there will already be buildup in the radiator and the heater core, and those can possibly get clogged by adding more.

[LD111]

That is I gathered. I will leave it out. Thanks.