Like many others, my 2012 Outback 2.5i Premium overheated for the first time on a long highway trip after idling for 15 minutes, waiting for an accident to clear. It has only 65K miles on it. Approximately 3 weeks before the road trip, I had installed the Aisin TKF-006 timing belt, water pump, and thermostat per the Subaru recommended 105 months/105K miles. I was able to let it cool, add coolant and successfully drive it home with the heater set to high. Since that one occurence, my troubleshooting has found the top radiator hose gets very hot and very hard and the lower hose is much cooler, until I continually squeeze the lower hose, and it also finally heats up. I have also observed coolant and air bubbles going into the overflow tank on 2 occasions. I suspect a blown head gasket. I used a block leak detector and the fluid remained completely blue. I retested using a 2nd tester and different fluid with the same negative test result. I then used a spill proof funnel to burp the system and found small, champagne bubbles streaming into the funnel, even at 195 degrees as measured by my OBD2 tester. As it warmed up to 208 degrees, the radiator fans came on and the temperature dropped to 198 and both fans turned off. The tiny bubbles continued to stream into the funnel until I turned the engine off. When I squeezed the top radiator hose, lots of bubbles came out. As the engine cooled off, the fluid in the funnel drained back into the radiator. Are there more tests I should perform before replacing the head gaskets? I can rent a compression tester, but I don't have access to a cylinder leak down tester. I am planning to replace the head gaskets myself, using your excellent videos as a guide. Thank you.
the 2010 to 2012 Outbacks and Legacys use the MLS turbo gasket from the factory - ive done a ton of these in the last couple years. no headgasket is going to last forever on an NA EJ25 even the turbo gasket. honestly at least when the single layer gasket fails it is usually just a external oil leak, which while annoying isnt a big deal and gives the owner plenty of time to fix, when an MLS gasket fails it overheats and needs to be fixed right away. - and some customers end up nuking the engine because they keep driving it overheating...
We work on these all day every day and it's very common for the head gasket to intermittently fail and never be detected with conventional means. It ALWAYS ends up being the head gasket in our experience.
I had my hose pop off after a tstat replacement. I never had water in my oil or bubbling in my radiator or overflow tank. I drilled 2 small holes on the edges ot the tstat and 2 years later still driving normally, This relieves any air behind the t stat. No other issues since I have 185 k on the car. 2011 Forester XT
My experience with the same platform - USDM 2012 EJ253 with ~120k miles on it, it overheated exactly one time so of course I freaked out about it being the head gasket(s) and had it towed to my mechanic immediately (shout-out to AAA, I love not having to pay towing costs out of pocket and super professional service.) He said he ran it for over an hour and there was no overheating, he thought it was just a fluke with a stuck thermostat. I still had a bad feeling about it and I had the time to pull the engine so that’s what I did. All of the parts were from Six Star or Aisin, I tore everything down short of splitting the crankcase and disassembling the valvetrain because the machinist said that both heads passed leak tests perfectly well. Ultimately it was no more difficult than the EJ253 from a 2009 Legacy I did previously, the only differences were a few parts being different shapes and materials, so if you would be confident following existing guides for an older EJ253 but not this, I can assure you it’s almost exactly the same and you should be fine doing the work mostly on your own (go get the heads decked at an actual machinist!) It’s been a year and a half and nearly another 20k miles and everything has been going swimmingly other than the CVT valve body solenoid debacle and a few minor external fluid leaks. Call it anxiety or call it trusting my gut but I’m VERY glad I did the work when I had the time and just enough money for the parts. Endless thanks to MrSubaru1387 and 1A Auto for extraordinarily good guide videos and big thank you all of the super helpful people in the Fifth Gen Legacy FB group for answering my super specific questions. I wouldn’t be where I am without awesome pro-DIY RU-vidrs and groups (and Harbor Freight lol.)
If you need to drive the car and can't fox it immediately, you can drill holes next to the weep hole in the thermostat and even go further upgrade to 140 degree thermostat. The combustion gasses bubbles can collect in the water pump and around the thermostat keeping it from getting hot enough to open.
My car had the exact same issue, I didn’t know better so they did the gasket change but after learning everything I think now I could have just tried this first. I was having a P0171 code before it happened but have checked and replaced tons of stuff but it’s still coding P0171
My sisters 2012 Outback had this broken neck issue. I replaced the radiator, hoses, thermostat. New coolant, used no spill funnel. After running and driving for several hours, no issue. But, was checking fan operation, and turned on A/C, secondary fan did not operate! Blown fuse changed, second fan operating. I think the car overheated and blew the hose/neck because under load with a/c on and only one fan it just couldn’t keep cool. Car has been doing fine for several weeks now. Just one more thing to be aware of.
The upper flange plastic got super brittle (could snap it with fingers) on mine and it broke off, letting hose slip and spraying coolant. Fortunately wife noticed steam and shut the car down before it overheated. Head gasket was fine per the mechanic🤞
From my experience and research, head gasket failures still happen even with the improved gaskets on 2010-12 Outback/Legacys. It seems that they don't fail predictably like older models. I hear of failures at
Once the engine got hot and everything expanded the gasket started leaking most likely. Do you not use the combustion leak/block tester? Either way I agree. Trust your gut. Good video 👍
Im about to buy this year and model timing belt already done along with the front frame. 144k km so a few years away, it seems, for this problem to arise.
Great video as always! Exact Same problem with my 2012. My question is why didn’t the radiator cap relieve the pressure before my hose blew off? Seems like it should be designed to do so?….
It usually would but at high rpm or high load up a hill it may blow combustion gas into system faster than it can release it. At the cap. And the bubbles may not make it to the top of the system in time so it pushes coolant out which is harder and slower to push out than air so that helps it build psi faster too
@@MrSubaru1387 I'm asking this question from an educational stand point. If the thermostat was stuck closed how would the symptoms vary from what you're seeing now? Thanks in advance if you answer this.
2009 EJ253..Haven't gotten the bubbles yet but at 159k starting to get minimal seepage on bottom of driver's side cylinder head. Head gaskets have been replaced at around 100k by Subaru. Gasket material appears to be the MLS but I'm still preparing for it. It's not "if" but a matter of "when" it fails
If you were doing the cylinder leakage test on a STI/turbo Subaru with the coolant expansion tank. Where would you look for bubbles? Expansion tank? Or radiator?
Which turbo gasket do you use to upgrade? 11044AA770? I just found you can buy the 2018-2021 STI gasket, 11044AA910, for just $40 a gasket. I wonder if it is revised to be better in any way. PartSouq has pictures. All passages look the same. There is a change to how the layers are crimped together. Instead of little outer tabs by the oil passage side of the gasket, they are crimped next to the outer head bolt holes in the coolant gallery area. The color of the metal seems slightly different as well. Also there are four little notches at the top of the gasket instead of three. The gasket material on the metal is laid slightly differently too. Anyways, just figured I'd share after I went digging, hahaha.
2010 outback 2.5i. So frustrating did the same tests. Combustion, leak down, compression all indicate engine still within factory specs, but still engine is acting like it has a bad head gasket. Replaced leaking spark plug tube gaskets and valve covers. Airlock of the thermostat when the heater is used. But happens intermittently. The engine has 162k with updated gaskets that came from factory. Bummer that this happens.
How would you assess a vehicle health after its been driven with low coolant and was noticed at a stoplight it was overheating due to ruptured hose mid drive? Where would it be a good start to tell if any damage was done, checking the oil ? doing compression test ? sending the oil for lab test ?
I had a Chrysler 300 with a 3.6 that came in with a huge coolant leak, pressure test showed the oil cooler leaking coolant (common problem). Replaced it, and customer came back a day later overheating, coolant low. I checked the engine with the blue block tester fluid, it stayed blue (spark plugs are not accessible with the upper manifold on, can’t do a leak down test). “Must have been an air pocket”. Refilled the system and sent him home. He’s back again the next day, overheating. I use the blue fluid (still nothing), I run the engine until it’s almost overheating and test it again (fluid turns green!). Turned out the head gaskets only leaked when they were hot from sustained driving and sealed up ok when the engine was cold.
Recently had the exact same issue and was stranded but luckily had my 2011 with 130k towed to a Subaru dealership. Question if you can answer it please...my receipt has a part number for the 2 new gaskets as 11044AA770. Can you confirm this is in fact an MLS gasket part they used? I called the shop after watching your video to request they use an MLS and they assured me they have upgraded their gaskets to MLS for repairs but I cannot tell when I look up that part number up online anywhere that it is MLS. Thanks. Your videos are awesome.
You're saying that one of the indicators of combustion gases getting into the coolant system is the upper coolant hose backing off from the radiator... Why would it do it, if there is a radiator cap that is supposed to bleed all the extra pressure?
Thank you for the informative video. In my vehicle (ej257, 152k Miles) I observe bubbles in the white coolant overflow tank after engine is at the operational temperature. I also did combustion gas leak test, and the blue color of the test solution turned to yellow. Is that enough evidence that I need to replace the head gaskets? Probably, it is but figured it's better to ask before I pull the engine out.
Did you finally replace the head gasket on your brother's Subaru and did that fix the problem? I have a 2012 Outback with only 65,000 miles, and it has the same exact symptoms. Low mileage, but lots of short, stop and go trips over the last 13 years.
I've been watching your videos for couple years now, always great content. I noticed that 2010 Outback in UK comes with keyless entry and push start button. From your wealth of experience, do you think it's possible to buy parts from UK version and install it all on US version? Or its impossible? Thanks for your input!
Question i have 2010 outback 2.5 premium. No white smoke nothing leaking did oil change no coolant in oil pan but radiator is mixing . But car not overheating. Someone told me if the radiator failed the trans fluid is being pushed into the radiator? Can anyone confirm ? 286xxx miles but theres no symptoms of a bad head gasket
They can go bad in different ways. external oil leak, coolant in the oil and exhaust gas in the coolant which causes a lot of pressure in the cooling system, that how mine went bad.
Can you please expand upon this? As far as I know, my 99' Forester has the OG 253 and is MAF. 00' and newer are 251s. What about the 253 do you not like and what are the differences?
@@jimrossabrena7955 I think the 251 is SOHC and makes less power. 253 is DOHC with (?) variable valve timing. I am not sure though, dont take my word for it.
@@Obv1ously both the EJ251&253 are SOHC. The 253 (with the exception of the first few that were made) introduced AVLS which with that brings the valve stem guides being pulled and a few other annoyances like issues with the AVLS oil solenoids and etc… the 251 is just older and doesn’t have that. Of course it has the head gasket issue but with the right gaskets you won’t have this issue. The EJ25D is a phase one motor commonly found in 95-99 outback’s, foresters, legacy’s. That engine while cool does have its inherent issues with head gaskets and usually needed premium gas which a lot of people failed to do. The reason it required premium was something to do with the active lash adjustment found in those motors. To be clear the 25D is phase one, 251 is phase 2, 253 phase 3.
Hey there MrSubaru! By any chance (I’ve got a hunch I know the answer) do you know the FA20 that’s In the 13 Fr-s/Brz? I’ve got one that’s giving me a run for my money and I’m about sick of it. Wondering if something that may be super weird to me may be a big red flag to you!! If this interest you, please feel free to respond lol as it’s been almost 5 months and many many dollars of nothingness thank you
My 2010 Outback head gaskets are bad. Does anybody have any recommendations for a shop in the Los Angeles area that specializes in Subaru and can replace them?
Hello Mr.Subaru New Subscriber been a Honda owner for the past 20yrs Thank you for your vlogs Just purchased a new 2023 Crosstrek premium with a 2.0 Boxer. It has a stop start feature how would this feature affect the longevity of my engine starting and stopping all the time I'm able to deactivate it only for one trip at a time each time I restart vehicle it defaults to on.it took me 20yrs to leave Honda for Subaru lol.
Can't it still be a head gasket even though it passed the leak down test as that test only uses 100psi yet a running engines cylinder pressure can range from 200-1,200psi?
Yes. My forester xt would only pressurize cooling system if I would boost the engine. If I drove it under light load (no boost) I wouldn’t have any bubble in my overflow bottle. Brake boost the engine and would have tons of bubbles.
Why is it always head gaskets with these vehicles? I love the idea of Subaru and the vehicles overall, but it's so expensive and common for these vehicles to blow head gaskets.
This exact same thing is happening to my 2.5i. Actually just finished replacing the head gaskets tonight and still having the same issue. Starting to think I need to aggressively burp the coolant system, or maybe there is a coolant flow control valve that is malfunctioning. New head gasket, water pump, all belts. Also verified heater core isn't clogged. Running out of ideas, so if anyone has been able to fix this I'm all ears. 😧
Drill 2 holes on either side of the weep/burp/bleed hole in the thermostat. And remove the plug on the weep hole to open up that hole to allow the bubbles to get out of the thermostat/water pump area faster. It will help the whole system bleed better. It also helps if you have the combustion gases. If you do have head gasket bad again. You can drop down to a 140 degree thermostat on rock auto or wherever you can find it and drill the holes and it will help the thermostat definitely stay open
The main reason head gaskets blow on Subarus is because of poor EGR maintenance. Having a bad EGR will cause your car to run leaner. If you getting leaner it can heat up the cat (melt) and clog it up causing back pressure and heating up your head gaskets and eventually burning them
My 2007 Subaru Outback has a slight constant shake, slightly worse when turning left. Changed wheel bearings but the problem persists. Had a couple of mechanics look at it but they were unable to sort the problem. Could you please help? Thanks
Hey Mr Subaru. I have a 2013 3.6 Outback and I was doing an oil change yesterday, and noticed that it is indeed seeping some oil from both head gaskets, driver and passenger side. It has about 155k miles. It's not leaking profusely, but definitely seeping oil. If it seems to be leaking oil externally, do I have to worry about cooling issues in the future as they get worse? Thanks!! Great video, as always.
I have the same motor, but my seeps from the timing chain cover, I did have a power steering pump leak that looked like it was coming out of head gasket.
@@Jordan__Sloan I have a slight leak there as well, but very minimal. Extremely common on the H6's. Same with the power steering pump leaking. That will get all over and get all caked up.
Heh, if you work on a Subaru, you just expect those old Subarus to have a head gasket shot. If you work on a Nissan, you just expect to work on their broken CVTs.
@@Davidsmithisyourdad Still, a Subaru is going to Subaru. Glad that all the other car makers use different engine types for different methods of working on cars.
@@Davidsmithisyourdad the subject car in this video had over 200k miles before the gaskets failed. Not all Subaru gaskets fail, but it is a problem area. What car with 200k miles doesn't need a significant repair at some point?
