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2020 Subaru Outback Premium with sunroof, navigation, and cross traffic alert
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Discussion Starter #1
2018 Subaru Outback 2.5l Premium with 5K miles. After a 150 mile trip under 84 degree conditions, I smelled coolant after I parked my car in my garage. I checked the coolant reservoir, and it was level at the max marking. This morning I checked it again, and the coolant level when the car was cold was midway between Min and Max.

Do you think that this is a sign of the "dreaded head gasket" problem with Subaru engines? Or, could the high temperatures and internal pressures cause the coolant to become overfilled in the reservoir, leading to an escape of coolant to the atmosphere around my vehicle.

Don't know, worried. Never experienced this before with a new vehicle! :surprise:

PS No sign of coolant leakage on garage floor. Oil fill level appears to be normal.
 

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03 H6 OBW & 06 WRX Sportwagon
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first, check the coolant level in the radiator.

you may have a pinhole leak or some seepage - the dealership can pressure test the system. They may even be able to find some staining or wetness somewhere under the hood.
 

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2016 Outback Premium 2.5 CVT w/EyeSight+SRVD
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I checked the coolant reservoir, and it was level at the max marking. This morning I checked it again, and the coolant level when the car was cold was midway between Min and Max.
Totally normal (for any car). Coolant expands when heated. That's why the reservoir is also called the expansion tank.

The Owners Manual even states (with illustration) that the correct coolant level is anywhere between the Min and Max marks (cold). You have read the Owners Manual, haven't you?

Do you think that this is a sign of the "dreaded head gasket" problem ...
No.
 

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2015 Legacy 3.6R ES, 2014 Forester Touring ES, 2005 Jeep Liberty Limited
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Just relax and enjoy your vehicle you are becoming way to zealous. Subaru not out to get you and definitely no conspiracy.

Laughing at oneself and with others is good for the Soul!
 

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2018 Outback Touring 2.5
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Our '15 Forester often had "the smell" but the "cold" coolant level never varied except for maybe very small amounts. I was also concerned that I had a head gasket issue. Traded it on the '18 Outback, and no smell from it so far. IMHO, it is just the slight amount of vapor escaping from the overflow tank as it "breathes".
 

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2020 Subaru Outback Premium with sunroof, navigation, and cross traffic alert
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Discussion Starter #6
Our '15 Forester often had "the smell" but the "cold" coolant level never varied except for maybe very small amounts. I was also concerned that I had a head gasket issue. Traded it on the '18 Outback, and no smell from it so far. IMHO, it is just the slight amount of vapor escaping from the overflow tank as it "breathes".


JRobyn, i want you to be right about the coolant odor that i detected. Maybe the overflow reservoir went over max level, resulting in a trace release of coolant.

Btw, i made an appt w dealer on Wed to pressure test my coolant system


Sent from my iPhone using Tapatalk
 

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2007 2.5 L Obsidian Black Outback XTL
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If it was a head gasket problem then the cooling system would either be blowing or sucking through the radiator as the engine is running. Also it is likely that it will quickly sludge up/gunk up the coolant with exhaust gases. You might even be able to smell steaming radiator coolant from the exhaust.

I had a car that had a bad head gasket; when the engine was cold I could take off the radiator cap and the coolant would surge up and down in the radiator while the engine was idling.

On a new car (less than a year or two old) the coolant should be bright green with no sludge or deposits at all inside of the radiator or the expansion tank.

If you think coolant is pushing out in to the expansion tank too much then it is also possible that you are; 1) overheating or 2) have a bad pressure relief on the radiator cap.

Also, check your oil to make sure that it is not contaminated with coolant, it would be whitish if coolant was making its way in to the sump.

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If you have seen pictures or videos of a Boxer engine with the heads removed you can identify where a head gasket problem happens. It is usually between the cylinder and the water jacket around the cylinder. There is a minimal amount of surface area for the head gasket to isolate the two areas. A bad head gasket usually fails at that point.
 

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2016 Outback Premium 2.5 CVT w/EyeSight+SRVD
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... the coolant should be bright green ...
No. The proper Subaru coolant is dyed blue, and its corrosion inhibitor package is incompatible with the older green variety. Do not mix the two.

If you have seen pictures or videos of a Boxer engine with the heads removed you can identify where a head gasket problem happens.
Not applicable to the current FB-series 4-cylinder engines found in Gen 5 Outbacks.
 
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2017 2.5i Premium Crystal White Pearl with Ivory Cloth, with Eyesight and self dimming outside mirrors.
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No. The proper Subaru coolant is dyed blue, and its corrosion inhibitor package is incompatible with the older green variety. Do not mix the two.

Not applicable to the current FB-series 4-cylinder engines found in Gen 5 Outbacks.
Thanks, Tishers had me believing my memory had failed me again.
 
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