I just installed a block heater in my 2005 RS and, as per
Subaru instructions, added a bottle of coolant conditioner
while refilling.

The conditioner was full of lumps of putty-like material, even
after shaking the bottle vigorously. Most of the lumps would
smear out if pressed between my fingers but some of them
were pretty dense.

Is this normal or will it block up all my coolant passages ?

Does Subaru really still recommend that stuff?

It'll get into the crevices where gaskets are. Yes, still recommended. GM uses freaking pellets that look like dog food.

Yes, it is still recommended. But I talked to a Subaru tech in a dealership and he was very familiar with the RS leak, and he told me that he personally recommend me not to use it unless I use coolant. Plus the fact that that thing looks like shiet so I didn't put it in when the coolant was changed at 15k (ya I am a maintenance freak). So I just left my that bottle of stuff in my garage.

he told me that he personally recommend me not to use it unless I use coolant.

What does that mean? Of course you use coolant.

What does that mean? Of course you use coolant.
:lol:
Use coolant = there is a leak somewhere, and the level of coolant goes down as you drive the car.

The Factory said IF the dealer installed the Subaru conditioner in my Forester that any weeping of coolent from the cooling system ie head gaskets etc will be waranted for 8 years or 100,000 miles. That is stated in writing and it would be stupid of me NOT use it and I did. Any service department person telling you not to follow the factory recomendation has a different agenda than the factory.

Ah...good ole 2.5 headgasket leak...least there is a TSB

The Factory said IF the dealer installed the Subaru conditioner in my Forester that any weeping of coolent from the cooling system ie head gaskets etc will be waranted for 8 years or 100,000 miles. That is stated in writing and it would be stupid of me NOT use it and I did. Any service department person telling you not to follow the factory recomendation has a different agenda than the factory.

The leak problem is for the 2.5. My WRX is a 2.0L turbo, and there was no recall. This engine is used everywhere else in the world and no other places recommend that bottle of conditioner. I don't think I am stupid to NOT put that bottle of jelly into my cooling system.

I may in the future. If I see many people reporting head gasket leaks in the WRX. So far I haven't. And it doesnt' seem like it is a problem with the WRX.

Gunner: Yes I have a 2.5L engine that received the letter stating that any weepege would be warantied if the dealer installed the conditioner. I am under the impression that the Factory recomends it for your car too. If I am mistaken then sorry but, if Subaru does recomend it for your car then my statements stands that not doing so goes against factory rcomendation and dealer personel are NOT doing the customer any favors. MO Ed

Some tech told me the conditioner was only for the problematic 2.5RS models and using it on my WRX would make the gaskets too soft or something.

I got all that when I tried to buy oem subaru coolant and the conditioner. He said, just buy the green stuff, and you don't need the conditioner.. : )

I figured that if Subaru thought it was important enough to put in all the time, they'd put it in their coolant. So I use Subaru coolant and blow off the conditioner.

Instead of guessing just email www.subaru.com and found out the best answer

Subaru calls it conditioner because if they called it what it really is lots of people would complain. It's really STOP LEAK! Having that stuff running around in the coolant really is no big deal. It does nothing until the coolant starts leaking, then & only then does that stuff thicken up to stop the leak. It's been in my 2000 Forester for close to 30,000 miles with no ill effects. It's not in my XT & won't be unless Subaru cares to extend my headgasket warranty. ;)

Chuck

The conditioner was full of lumps of putty-like material, even
after shaking the bottle vigorously. Most of the lumps would
smear out if pressed between my fingers but some of them
were pretty dense.


Yeah, I wasn't too thrilled about putting that stuff in either (30K mile service). I'm the type of tightwad that after putting that stuff in will add some water to the bottle, shake it up, and pour it in just to get the last bits and pieces...and that's exactly what I did. :( :D

Nothing to lose sleep over, but I read that Subaru recommends it for the 2.0 too.

I've had the conditioner in for ~2X coolent changes (coditioner added at each 30,000 milee change as factory recomends) and not a hint of a problem in 61,000 miles. Now at 90,000 and going strong. I would suspect that since GM, Ford and? others do it at the factory that maybe Subaru is now doing it also?

Waking up an old thread...:D
My 01 legacy now has 150K miles. Recently it started to drink coolant. It was not fast, 1 qt per week, but consistent. I can also see faint white smoke off of exhaust. So I added a bottle of Subaru coolant conditioner in (actually 1/2 of the bottle got spilled). A week later, I flush the coolant out, now it has just water. But the leak seems stopped.
Is that possible, just with that conditioner in for a week (like $1.40/bottle) and it worked?

I replaced my coolant the other day and added a bottle of conditioner and noticed the white lumps that looked like tooth plaque. I would not worry since I still poured the whole bottle in, the heat from the coolant is going to melt the lumps plus it required for my car.

the water pump will take care of the "lumps" too.