My 2005 Legacy GT is burning coolant

Do you have any noticable oil consumption?

Almost none. In 5k miles the engine burned about .7 of a quart. The level was just over LOW from FULL. So however much it takes to fill it from LOW to FULL, substract from that about 20-30%. So I'd say I'm one of the folks with barely any oil consumption.

Dropped her off this mornin', they'll have a look-see. They told me last time they did a hot and cold pressure check and supposebly it came back fine. What else could it be besides a headgasket? Like I said, coolant level stays steady if I don't drive, absolutely no drips on my driveway.

That's a bit of a mystery. I had also disappearing coolant on the old engine - no external leaks at all, checked many times. Had cracked ringland though, and theory is that could also caused coolant consumption (in addition to fuel dilution and oil consumption).

I want to scream. Dealer just called me and is claiming that when cold, the coolant level is right at the dot where they marked it.
Which is bullshit since I sucked an inch worth of it out myself so they wouldn't turn me down saying "it didn't go down enough".
I'm leaving for the dealer as we speak so I can see it myself. I am pissed off beyond belief.

Very normal. I didn't suck any fluids when I was fighting them, but had similar experiences. Like oil below L being described as "full".

Alright, I guess I feel a little better, I just got back. The Subaru master tech seems kind of a likeable, trusty guy
We both looked and indeed the coolant level was where I saw it when I dropped it off this morning. The car actually sat out on the lot on an even surface and when he checked it outside the level was right at his marking. When he brought it in it dropped because of the ambient temperature difference, it was considerably colder in the shop. The tech basically asked me to tell him what I had going on, since previously I had been working with one of the monkeys behind the service desks. I told him about having to compensate moderately twice over the span of 4 months and told him about the UOA and traces of glycol. He told me that so far he hasn't had problems with blown headgaskets and that he routinely has to top off coolant when customers come in for oil changes, due to water in the coolant evaporating, temperature differences and such. Is this really a "routine" thing? The ticket has definitely been noted and he did tell me that if something does turn out to be the problem after my warranty, it will be taken care of.
So maybe that is my problem, just normal, routine coolant level varying due to temperature variation and water evaporating? And my recent UOA turned me paranoid. But I still can't explain where that trace amount of coolant showed up from. I guess I'm not 100% sure I didn't use a common funnel and the amount that showed up in the analysis was only 0.84 so nothing big.

My gameplan is to basically just watch the coolant and do another used oil analysis after this oil change.

So ... anyone else here have to top off their coolant with about 6-8 ounces every once in a while?

First got the car, thought the top mark was where the level was cold. Oops. Coolant down to the lower marking when cold over time, and then it stayed there. Check out how high the level is when hot, and you will see why you lose coolant if you fill it up above the lower mark when cold.

Least that's been my experience.

Yeah, the tech overfilled it good too
I'll keep an eye on both hot and cold levels. Maybe it was a fluke.

Just thought I would update this thread with a "verdict".
The coolant is basically ... evaporating. It's not in my driveway and it's not in my engine. Best we can figure out is the distilled water evaporates during the winter months because of the big temperature difference. Like I said, the mysterious disappearing coolant only happens during the cold months. There is at least one other member here with this little "problem".
The two recent used oil analyses both came back with absolute zero glycol reading.
My advice to you is watch your coolant overflow level and keep it at least somewhere between the High and Low. Oh, and don't keep dumping straight OEM coolant, add distilled water to the mix too

I always had mystery disappearing coolant.

Cause? Dirty radiator caps. Cleaned and problem solved.

Did you check yours?

That I have not checked.
I'll also say that the overflow tube that goes in the overflow canister is not sealed, at least not mine, so I can definitely see it evaporating around there. I think I'll throw some silicone around it.

Originally Posted by fishbone

..........Like I said, the mysterious disappearing coolant only happens during the cold months...........

Maybe a small leak at the HVAC heater core?

I have an 05 LGT and also have experienced the disappearing coolant act. I know this thread is kinda old but just wanted to voice up a fellow LGT owner. I am glad I found this thread as I was pretty concerned. I have only had the car during winter so I have no basis for hot weather coolant levels. I did an exhaust gas anyalysis of the coolant and found none, so I was a bit baffled. Hope it is just the distilled water evaporating

I noticed my coolant was a tad low in my overflow just other other day too. Bumped it up to midway between max./min on the res. I noticed a painted on yellow line right in the middle. I assume that is to mark normal fill level at ambient temp. Added a touch of OEM coolant. We'll see where it goes.

I've not noticed any disappearing in the 2 summers I've had the car.

Where do you guys get distilled water? I've only added straight coolant from the dealer. Not a lot, just enough to top it up this time.