Coolant consumption 2009 legacy

[Kilzon]

Hello, I have 2009 legacy 2.5 limited. It consumes coolant without showing any kinds of leaks. I have no milkshake in my oil, no blue smoke, no bubbles in reserve tank. I replaced timing belt and everything what is related to this procedure (pulleys, water pump, etc). Mechanic said that there was a leak in water pump and since he replaced it we expected that consumption will stop but it only became worse. He said that I have external leak in head gasket but only oil is leaking. I haven't talked to him about coolant leak yet. 

Has anyone faced with this problem before? I can't find the reason of coolant consumption. 

[apexi]

I haven't heard of this in my time here. How much coolant are you consuming?

Heater core leak inside dash? Blue smoke is oil, is there excessive white smoke? In your shoes I'd buy my own cooling system pressure tester, where you can pump air into the cooling system and look for leaks everywhere, especially @ radiator too.

[NORULZleggy]

Head gaskets is what I would guess. I know from experience from my 08 N/A those years has phase II paper gaskets and the would go. I had the same issues and drove the car for years keeping and eye on things till I pulled the motor and replaced everything.

[Kilzon]

So, I keep coolant on “full” And have to add half of reserve tank every two weeks.
There is no signs of  leak in head gasket (internal). As I said, no any kinds of smoke(no blue, no white smoke), no milkshake in my oil, no bubbles in reserve tank. Also I haven’t seen any plunges of coolant under my car

is it possible that coolant evaporates somehow ? 

On 10/19/2022 at 12:53 PM, apexi said:

I haven't heard of this in my time here. How much coolant are you consuming?

Heater core leak inside dash? Blue smoke is oil, is there excessive white smoke? In your shoes I'd buy my own cooling system pressure tester, where you can pump air into the cooling system and look for leaks everywhere, especially @ radiator too.

. 

[Kilzon]

On 10/19/2022 at 12:53 PM, apexi said:

I haven't heard of this in my time here. How much coolant are you consuming?

Heater core leak inside dash? Blue smoke is oil, is there excessive white smoke? In your shoes I'd buy my own cooling system pressure tester, where you can pump air into the cooling system and look for leaks everywhere, especially @ radiator too.

Could you suggest any pressure tester ? 

[Max Capacity]

 

Just saying, that Full line is the "Full" when "HOT" line. 

 

The weep hole in the water pump may be dripping onto the undercover pan, You may not notice the leak under car as it blows away while driving. ?

I agree with the Pressure test idea. Or, most good repair shops will have a HC tester they can wave around the radiator cap with the running engine to check for exhaust gasses in the coolant system.

[Rusty9]

You can buy a UV additive for the coolant. Put that in and run it for a few days then inspect everything with a UV flashlight. Pinhole leaks in the rad or fittings can evaporate before you see any wetness. Also seconding the use of a pressure tester. Parts stores carry them for free rental.

[Kilzon]

4 hours ago, Max Capacity said:

 

Just saying, that Full line is the "Full" when "HOT" line. 

 

The weep hole in the water pump may be dripping onto the undercover pan, You may not notice the leak under car as it blows away while driving. ?

I agree with the Pressure test idea. Or, most good repair shops will have a HC tester they can wave around the radiator cap with the running engine to check for exhaust gasses in the coolant system.

Damn, man. I thought that the “full” line  is when it’s cold.  

Considering this fact. Is it possible that coolant just evaporating somehow ? 

[Max Capacity]

It will over time, I normally top mine off once or twice a year, adding a small amount, not twice a month like you are. I'm wonder if your over filling it and its being pushed out while driving...?

[silverton]

There's no way that much coolant would evaporate over two weeks time, that's more like 9-12 month fluid loss. Even with the overflow bottle the system is pretty well sealed.  If it was being pushed it out, it would look something like a leak, as it generally gets all over nearby components and leaves a residue.

With it being minor, and no noticeable external leaks, you could have a small internal leak into the combustion chamber. Which would produce a thicker white smoke, not to be confused with normal steam from the exhaust system warming.  If you were really curious you could pull the spark plugs and see if any of them look cleaner than the others as an internal coolant leak will steam clean the combustion chamber. Are you positive there are no external coolant leaks? Are the tanks of the radiators wet where the aluminum is pinched on? If there is any "grey" slime looking stuff where the head gasket is; that would be coolant mixing with the oil.