2010 Outback Overheating Problems

[bodesoto]

Hey everyone first time posting, I’ve head this outback for almost a year now and has treated me pretty well till these last couple of months below if everything thats happenned and what me snd others have done to find the problem. Any help or direction would be great. As long as it can make a 5 hour drive back home in May I can probably fix whatever problem this might be if I can diagnose it.

2010 Subaru Outback 2.5L Limited 6spd Mt

77183 Miles

Feb 22:
Me and 2 friends were driving out to a trail head car drove for 30 minutes then overheated. I let it cool off and it drove fine the rest of the way. Didnt get me issues until

Feb 28th:
I met up with a Mechanic who was on campus and we replaced the thermostat with one from autozone and burped the system. Drove fine during short distances

March 8th:
only my 5 hour drive back home I mad it about 3 hours and the the car overheated and sprayed coolant everywhere. i let it cool then grabbed 3 gallons off coolant. At this point I was driving 30 minutes then the car would overheat so it would sit 20 minutes then I would top it back off. It took a long time but I made it back to home

March 10th:
-Replaced Thermostat with Subaru OEM
-Replaced Radiator Cap with Subaru OEM
-Flushed the system and put in new coolant
-Burped the system with spill free funnel

It drove fine in my home town for that week

March 15th:
Drove an hour to my sisters game no issues. I left there and had 4 hours to drive still

1.5 hrs in car overheats, I wait and then grab a shit ton of coolant because I know what I’m in for. I repeat that same cycle of driving 20-40 minutes and then at times the car would overheat but typically I would try to stop before that happens and then I would replace the missing coolant. i was supposed to get back by 5-5:30 made it back around 11

April 2nd:
Made an appointment with mechanic

Calls the next day and says the cooling system looks fine and that it might be an internal headgasket failure but he doesn’t have the tools for that

April 9th:
Appointment with new mechanic who can test for the head. before I got there I drove it for 40 minute straight in western NC mountain backroads with no issues then stopped for a lil and drove another 40 with 0 issues

New mechanic said he tested the head gasket and said it was fine. He also said he couldn’t get it to overheat. He said it idled for 2 hours fine He also said that he thinks there was just air in the system. I’m like dope maybe it was that easy

Today April 13th was driving 50 minutes out to a trail head taking highway. 25 minutes in the car overheats……. Luckiky I still have some coolant but I mean seriously. Brought it to 3 people and nobody can figure out what is wrong with it. My guess is that it has to be the water pump at this point.

So if your here after reading that essay these are my main questions

- Should I go to a subaru dealer
- Is there any other things to test to see whats wrong
-Any body have an issue like this
- any way to get this thing to drive 5 hours

Also I’m pretty mechanically inclined to fix it as I have a Diesel Heavy Equipment Degree but I just dont know what the hell the problem is

Any help is appreciated thanks


Summary of everything thats been done

-New OEM Radiator Cap
-New OEM Thermostat
-New Coolant
-Tested for Head Gasket no problems

 

[bmart]

Head gasket is easy to figure out. You will have oil in coolant and/or coolant in oil...or you will lose coolant to atmosphere. Do you have any of those?

If there is any air in the coolant system, you will continue to overheat. Air must be gone.

Did you (or anyone) touch ANYTHING before the Feb 22 issue and is this the absolute first time?

When you added coolant, how much and did you get all of the air out. "Cooling off" and being okay just isn't a thing.

 

[bodesoto]

When I replaced the thermostat I also did an oil change and didn’t notice coolant nor oil being mixed this was along side a coolant system flush with distilled water and the coolant wasn’t dirty at all

Also I brought it to one of the mechanics and he said that he tested the head and said that it was fine and that he believed that it was just air in the system too

It overheated the day after on a 30 min drive….

Nobody did anything to the car and nothing irregular happened before it overheated Feb 22nd it was very random and it wasn’t leaking coolant or exploding coolant everywhere at that point.

Me and a few others have burped the system on different ocassions and ensured that all the air is out of the system and yet I find that if I drive longer than 30 minutes doing highway speeds it overheats

So basically my process of adding coolant is this:
I see a red thermostat pop up on my dash (this gen doesnt read the engine temperature) and I pull off the next exit I see or just on the side of the road if there isn’t one close.
I turn off the engine and put on the battery and put on max heat to cool the engine until the light goes away. I pop the hood and normally coolant will have sprayed everywhere
Typically the overflow tank looks overfilled and is boiling
I let the engine cool for a while then open the radiator cap and fill it up to the neck and then I squeeze both radiator hoses for a few minutes adding coolant as needed then I fill the overfill tank between the min and full line. After that I do what the owner manual says and attach back on the cap and run the engine with max heat and rev between 2-3k rpm 6 times and wait until the engine is cool after that I top back off any missing fluids

When I have a spill free funnel the process is much simpler than this.

Head gasket is easy to figure out. You will have oil in coolant and/or coolant in oil...or you will lose coolant to atmosphere. Do you have any of those?

If there is any air in the coolant system, you will continue to overheat. Air must be gone.

Did you (or anyone) touch ANYTHING before the Feb 22 issue and is this the absolute first time?

When you added coolant, how much and did you get all of the air out. "Cooling off" and being okay just isn't a thing.