Thanks for taking one for the team! I’ve watched ChrisFixs video on it and it looked like a promising way to temporarily fix a head gasket leak but this is making me think it’s more of a luck of the draw and he got lucky.

In my experience it only works on VERY small headgasket leaks. My 1993 WRX was draining coolant tank once every few months. I used steel seal and it worked for 1 year untill I saved up enough to replace the headgaskets. My number 1 tip is add it to pure water and not to coolant !

I've only ever used Stop Leak once, on a BMW M54B25 motor. 01' 325i. Car had around 130k miles and a hairline crack in the head was causing coolant to weep through the aluminum, a few inches below the valve cover. I'd already bought a used, running motor to swap in, but as a joke with my buds who were there to help me swap the motor spent $30 on a bottle of stop-leak, bled/topped off with distilled water, and drove it around 100 miles. It stopped leaking. Drove it for another 30k before selling it, it never leaked during that time. Gave the used motor to the guy I sold it to (who became a friend) and told him what I'd done in case it ever started leaking again. I was genuinely shocked that it worked, and continued to work for another 30k before HE sold it. I'd never use it for a headgasket but that situation blew my mind.

Glad I saw this video. I have a 2000 2.5rs with a very early head gasket that's starting to seep on one side. Considered putting this in there to buy more time - will steer clear after seeing this!

Thanks for the advice with the video. I thought that would happen. Thanks for sharing. 👍

This product may or may not fix your head gasket leak, but it will definitely put silicates into your coolant since the active ingredient is sodium silicate. This can be a major problem if your car's coolant system is sensitive to silicates. For example, Honda uses non-silicate coolant, and adding silicates can cause water pump seal damage (causing a leak) amongst other major problems. Apparently Subaru is also sensitive to coolant contamination. Know what you're getting into!

Works for me, 2006 Honda pilot with 287,000 miles. Had a misfire in cylinder head 4 and 5.

I speculate that the Blue Devil did not cause the water pump failure, it was the pure water that did, meaning that it did not lubricate as well as anti-freeze would have. This is just a guess on my part, but what I have seen of the Subaru water pumps is that they are really simple-not much to fail.

One thing we know for sure: your work on the head gaskets and the coolant path will definitely seal up every possible leak! Thanks for the videos on seeing all of that done right!

Hey at least you tried. I can see where any sealer would have a problem holding back combustion pressure. These products work well on other leaks like external weeping or coolant to oil contamination. Same wirh intake manifold gasket leaks. We have an old grand caravan, it was weeping, i assume, between the lower intake and the head. Used a small amount of bars leaks and it fixed it immediately. For small leaks that are not urgent like this one, i used 1/3 bottle. That was 6-7 years ago. I also stopped running pressurized cooling in all of our cars by modifying the radiator cap or leaving the gas bottle pressure cap a little loose. Been doing this for years with no issues even in 95° summer days. No pressure means no stress on components.

I used Fusion Seal, which is a 2-part epoxy sealer that has a fairly lengthy application process, including flushing the engine with water first, and got another 2 years before the leaking came back. I'm now changing the head gaskets and everything looks clean.

Excellent educational content and video!!! Press On ✌️😎👍👍👍👍👍

This lines up with my experience with this style of headgasket leak, the combustion being pushed into the cooling system will just push anything trying to seal it right back out. I also think the water pump failing was more likely already on its way out and i don't see it as an extra cost either since it should be replaced along with the thermostat while doing the headgasket anyway considering the mileage.

Thanx for the heads up.

Thank you so much for doing this

Thanks for a great video! I have a Subaru Impreza from 2002 that has P0420 problems that is in the workshop for service as I do not have the opportunity to work on the car myself, so I look forward to your next video.

I've used the BLUE DEVIL power steering sealer on a GM leaking power steering pump and it works!

Holy crap that sucks man, it did go the mileage so can’t be to upset about I hope you do videos on the hole job cause I have a similar forester and just started getting into bigger jobs like that at work (head gaskets, timing chains, etc) so it would be awesome to watch. Thanks for this vid to cause I would of took my shot at that as well before tearing apart my engine

Hey Mr Subaru, I have a 2015 Forester with 90k miles, the block was replace at 76k miles for Oil consumption after that I’m doing my oil change every 4K miles, how I can prevent the head gasket issue?

*KSEAL* purple bottle. Works. I did on turbo diesel citroen with weak head gaskets

I did have pretty good results with the Bar's leave in Head Gasket sealer in a 1997 Outback 2.5l DOHC (just after I bought the car knowing it had issues) for about a year until the water pump failed, not sure if the small fibers got in and killed the pump seal or not. I went ahead and did a full reseal on the engine knowing I wanted to keep the car until it rusted out from under me.

Happy you're starting your shop homie! Blue Devil is definitely an emergency product and I don't think it works on our engines. I've known people that have used it on American cars and drove for a long time. Good to keep on your off road rigs if you need a get off the trail fix

Been following you for a while and cool to know one of my favorites is local lol

My understanding with the sodium silicate sealers is if you have coolant getting in the oil, the sealer will get in the crankcase and gel the oil.

Got a previa might wanna use this before trailering it for an hour

Thank you Mr. Subaru (I don't know your real name) for this. I hope one day somebody comes up with something that works.

I used this same product on a 01 mazda b3000 which i found the leak to be by cylinder one and its been running great with about 2500 miles on it and no issues and not having to refill the coolant reservoir every couple of days

Feels bad, I recently used this in my EZ36D engine and it did jack. Coolant overflow tank level drops a tiny bit every month or so I’m just going to run it as is.

A better question is what causes the gasket failure. PCV clogging and the resulting pressure build up is the common reason. I replace the PCV once a year. Yep it’s a overkill but the part is cheap, and my 2012 legacy doesn’t leak a drop.

I’d try it again!! Premium Sodium silicate works Very well If all the antifreeze is removed from the system. Leave the thermostat in but drive it for the day. And after that drain the system while warm and leave the hoses off for the night. if possible or a concern I’d bypass any heater with dual systems and or auxiliary water pumps during the treatment. I used it in mainly aluminum applications with MLS gaskets. I even used it on a boat that had rust on the spark plugs , it had thin heads from salt water in which I ran in a tub and kept the water around 200 degrees. I did a Range Rover that the ex came home with one day , a Subaru 2.5, a daily driver bmw N62 I’m still driving 30k later that was smoking pretty good, a caddy North Star, even a sleeved 4100 that was leaking externally as well. As for cat codes. Cat cleaners do work or tooo much sea foam has done wonders for me in a couple applications

Thanks!

Have the same problems on my 2011 Forester. Want to know how to fix the P0420 after replacing the motor

there is an pretty cool technology called CERAMIZER - patented technology at least it was designed here in Poland many people and mechanics prize it to the havens. HAvent tried it myself on my diesel but it seems to actually work pretty good. It honestly does the job. There are a lot of videos about this on the web. Maybe try this one next time?

Unrelated to this video, but about this Forester, did you film the replacement of that rear finish panel on the tailgate? I need to pop mine off to fix an issue with a loose switch bezel and would love to see how you approached that.

Hey I have a quick question my 09 forester has a heat shield problem , I watched your outback heat shield repair but I don't want to use steal wool because if a battery is put up to it it will set fire, I tried a metal clamp made it worse took it off was better then I tried a little screw but did not do a thing. I would love some suggestions?!?!?!

I’ve got a high idle of 1250 when warmed up on my 03 forester 5mt, any tips on how to fix it? Map sensor was replaced by old owner and PCV valve and hoses have been replaced as well as Idle air control valve

I’ve tried Blue Devil in 3 Subarus. In a 2001 Forester leaking to the outside it worked and caused no problems. Been a couple years still working. In a 1996 Legacy getting combustion gases in the coolant. It did nothing. No harm but no help. In a 2006 Forester leaking to the outside it stopped the leak. However it also killed the water pump, partially plugged the heater core and radiator. I was able to flush out the heater core but had to replace the radiator and water pump. So it seems to work on outside leaks but not combustion leaks.

What is the normal running temperature for a 2017 Subaru Forester premium.

Funny you notice a correlation between the stop leak and the waater pump giving out because I had the same experience on my ej205

To be fair, the water pump leak could have been caused by removing the thermostat and changing the flow through an old pump. As for Blue Devil (the type you used), I've seen it work. A friend's forester was slowly losing coolant and I detected a minor amount of combustion gas by-products in the coolant. Very minor bubbling as well. We flushed the system, added distilled water with Blue Devil, and he drove the car about 500 miles. After around 100 miles the loss of coolant and bubbling stopped.. He continued to drive the car for a couple of weeks until he drained, flushed and put normal coolant in. The head gaskets held up until he did an engine refresh about a year later. In his case it turned out to be a useful stop-gap repair while he gathered parts to reseal the engine, do the heads,,, all that. My feeling is that you need to heat cycle the engine a number of times to get this stuff to do its job. Drive the car for a while and see what happens. If the weather is warm, not much risk involved.

Why not use the Subaru cooling system conditioner/ stop leak?

A few decades ago I worked in an auto parts store. The guys that came in swore by Moroso Ceramic Engine Seal.

You have to find the cylinder that is leaking and remove spark plug and best results use the reg blue devil where you flush and use only water

At least we all know now to stay away from the Blue Devil.

Happy boxing bro

i think i have this same problem on my 99 forester GT. something is messing with the o2 or cat as i get little pops and the car stutters and i lose or get no power when i accelerate too much. so if i move the pedal 1mm it accelerates normally, 1cm it pops and stutters and does nothing, put it to the floor and it clears it's throat, pulls up it's pants and wants to break the quarter mile record. my heater sometimes works but only after i stop the car for a few minutes then start her up, then sometimes goes cold again after a few minutes of driving. then i find out last week i need a new head gasket and everything you mentioned here would line up with what's happening to my GT. crap getting on the 02 or in the cat clogging them up and my heating system playing up. i'll check the temps on the hoses after my next drive and see if the hose is over pressurised and the other is cold. can't afford a gasket to be replaced just yet but i'm also reluctant to put crap into the engine as i don't want to make it worse so in the mean time i'll keep driving like my nanna

Dang well that sucks. I think the headgasket on my 2015 wrx is starting to leak. Checked my coolant reservoir yesterday and it was below the low line, car was cold didn't start it sat over night. I check my car religiously as any other Subaru paranoid owner lol so i know it happened recent. Checked it again today first start of the day and it was almost not visible on the reservoir and my exhaust smelled a bit sweet. 😭

my 2008 Forester base model with the 2.5 and AT still doesn't leak any coolant or internal oil after 179,000. Yay!!!! ( Heh, just jinxed it)

So far it's working on my 06 Forester been 20k since I added thanks for all the good videos

Another great video! Would you say that this small head gasket leak might become a common issue on the FB20/25?

When you do your rebuild (I know you’ve done multiple times and videos) but could you basically make it a walk through (assuming a multi part video). And walk us through what you find, and would love to hear your opinions based on experience of the engine needs the machine shop. How do you check your mating faces, are you using the tech manual, does the manual allow for tolerance in head straightness etc… sorry and thank you

It worked for me: READ: I don't trust potions like this but I purchased a Subaru Tribeca after my wife's car was totaled in a near fatal crash (guys please don't let your 87 year old mom drive around!). Since the used Subaru was not worth the cost of a new head gasket job I reluctantly use BLUE DEVIL (the larger yellow labeled bottle). It saved my ass and that was back in 2017. I keep a block tester kit and check it yearly and it is still working. I am amazed to this day.

I had the 0420 code show on my "06 Subaru outback and was told of course that the cat was the most likely suspect. So I bought a cat on line and before I could put it in I did an oil change about a week ago and the code hasn't come back since. It was the one thing nobody mentioned in all the research I did. Not saying it will help you in your case but I often times forget to check the little things first.

I knew that the EJ engines had head gasket issues, but thought it was cured by the time the FB family of engine came out.....guess not. So are you just going to reseal the engine, or, and I would guess this will depend on the condition of the cylinders, are you going to end up doing a complete top end rebuild on the engine? Do you have a rough idea on the cost of doing a full rebuild on that FB25 engine? Used Subi's are astronomically overpriced, and rebuilt drop in engines are so expensive, you would think they were gold plated.

been fkn with cars for over 45 years, this is what i found out about stop leak, sometimes it works. sometimes it doesn't, but it never last. stop leak is to get u home from the side of the road cheap, not make something new again.

Good vid. What about Holts?

I'd also like to add the people selling blue devil don't know their product . it comes in two different size bottles for the amount of coolant and engine size being treated as well as some bottles say remove the thermostat and some bottles say you can leave it in . There's also a money back warranty if it doesn't work . if you choose to pursue it . Usually they try to talk you into a second bottle instead of your money back . You will have better results with sodium cilicate AKA concrete sealer which is found in most head gasket sealers at cheaper price . We try to talk our customers out of it but unfortunately there's more videos claiming it works then the truth like Mr Subarus vidoe .

This is why i will not own a subaru again had 2006 impreza 55000 miles needed gaskets traded it. best thing i did

6:48 that’s the only best was to fill a modern cooling system nowadays, especially on a flat engine vacuum bleed is the way to go…

Radweld ( UK ) is the way to go for cooing System leaks

Why doesn’t Subaru use a regular head gasket vs liguid sealer? Talk about this. Like your videos

Your using the wrong one use k seal it works all the time for me at the dealership

so... if the gas introduced by the small head gasket leak makes the thermostat lame, how do you avoid the same thing from happening when refreshing the coolant!? (without using a fancy suction system) Seems to be a major flaw and PITA.

Bro where shouts in SC are you located, SC here as well

Are you located in South Carolina? I'm in Texas and need a head gasket job done, I trust you over the other mechanics haha.

Thanks for saving me money! I sent a few bucks to share the expense.

if the only symptom is the thermostat not opening up, cant it just be a bad/stuck thermostat?

Blue devil is a bandaid at best . We used many bottles with hit and miss results with customers saying i just need it to make to the dealership to trade it in or I just need to buy time till I can afford to fix it . resulting in more damage because it still overheats . As far as a small head gasket leak it works but warped heads stretched head bolts or corroded head gaskts it's not going to fix it . Water pump failure is very common with this product it will seize and cause premature failure if any of the blue devils makes it past the seals of the water pump .. the same goes for your engine. If your head gasket leaks coolant into your combustion chamber it will lock your motor up if it set in the combustion chamber . It also stains Everything white when it dries like concrete sealer . If you leave it sit in a pan it will turn to gell and harden like plastic to the drain pan ...... that's really good for your radiator . That being said like Mr Subaru said its snake oil in a bottle . I can count on one hand how many miracles of success I have had with it out of a 100 bottles and you would have better luck sticking that one finger in your butt if you really want to stop a leak and save your self 50 to a couple hundred bucks for a gamble that's going to cost you more money in the long run .

blue devil works.

no only do head gasket sealers not work, they clog stuff up and make the doing the real fix alot more time consuming. ive done HG jobs and had to chip away tons of hardened up sealer in the water jackets. there no way any sealer is going to hold back cylinder pressures for long.

Dang!

Snake oil for sure

I was under the impression that this generation of engine did not have head gasket issues! Am i wrong? I have a 2015 Non-turbo Forester and want to do everything possible to keep it for 200, 000 miles!

Do you think this would work on an external head gasket leak?

Cant imagine how that product would have caused the pump to fail. As you note, it was most likely on its last legs. Put a new pump in for your mom!

Interesting that the dealer didn’t stock the water pump.. not all that Common to fail maybe ?

Subaru’s special “ conditioner” SOA635071 is the same thing lol I’m at 149 k on my EZ36 and haven’t added that junk yet… however I’m anal on my maintenance intervals…..

I had luck with blue devil but you need to leave it in the system the 50 min run time was not long enough for me either it took couole 100 miles to work

A lot of work on that thing to be done now… At least all the weaknesses should be worked out after your rebuild… Definitely not a job / project for your “at home do it yourself” mechanic.

I've killed a couple high mileage water pumps by pulling a vacuum on them. I know that's what killed them on mine not sure on urs but it's a poss

Very interesting, I wonder if this is the same stuff (maybe diluted a lot) that some junkyards use to seize engines. Can’t remember why they would but I remember someone saying they put something in the oil to essentially fill the engine with glass.

I suspect that someone already said this: there are two versions of blue devil. The one you used (the "poor and go") is complete garbage! Please, don't ask me how I know. The other product, more expensive, requires removing the thermostat and it WILL work if you follow the instructions. I used it on my old Impreza and wife's MDX with excellent results. No gasket leaks after it. The "poor and go" did the following: 1) killed my thermostat; 2) clogged my radiator (I ended up replacing it) and 3) caused me countless hours on cleaning the engine with vinegar - that was the suggestion by the blue devil folks - they are apparently aware of the quality of the "poor and go".

If the head gasket is leaking combustion gas into the coolant, how would any stop leak work? As the gas is going to keep blowing the sealant out of the leak. If the leak was from the coolant into the oil the direction would pull the sealant into the gasket failure and I can understand that working. But then you risk pouring silicon into your oil so…

Red Devil 🤣🤣🤣

People be joking about Subaru head gaskets. And it's actually true.

What causes a head gasket to go bad in the first place?

Diesnt that stop leak clog up your radiator, heater core amd small passages?

Did this exact stop leak with a customer car per their request. It was a 2003 Camry with the 1mz v6 engine that over heated after they lent it to a careless friend. Long story short it did not seal the headgasket leak. It did however do well at accumulating behind the thermostat and other hoses. Do not recommend

Mr Subaru, out here wasting his money on dodgy products so you don't have to. 😂

Found out someone sold me a Cherokee with stop leak in it. Pain in the neck.

Water pump may have just had some gunk and the flush plus the BD cleaned it off and opened it up. “Maybe”… but can’t say for sure without some sort of abrasive test. The suspended material in the BD somehow wore the seal out on the impeller shaft. I’m assuming BD has to be abrasive to some degree if it’s has glass in it. (Again that is just hypothetical and I have zero knowledge of what the actual material in BD is or if it’s even abrasive$ You obviously know this and probably thought all this through. I doubt it is reactive to rubber, that would be an obvious oversight on BDs part. But again they’re the engineers, we’re just the grease monkeys turning the wrenches and throwing poo on the walls.

Your water pump is done for

The only good thing that crap did is make It so we get to watch you replace a water pump.

not even 1 second in and i know it wont work. since ive tried this on my 99 outback 6 years ago

TL;DR: The Bar's Head Gasket Stop Leak & Block Repair has fixed a quite severe external head gasket leak of mine and I can fully recommend it. I have an '05 Outback with an EJ253 with 368k km on the clock. I have only owned it for a bit less than a year now, and in the beginning I noticed that coolant was dissappearing somewhere. It wasn't much, so I just thought to myself that I'll just keep an eye on the level and monitor the usage. Then I started having to add almost a liter every day, and I started to smell burnt coolant at stoplights. A few months ago on my way back from work I noticed that the temp gauge started rising a bit. Having experience from shitboxes, I took my hand to the air vent, and almost immediately felt the flow go from hot to cool. That's when I knew to stop after 15km of driving, and I ended up having to fill about 2-3L straight into the radiator. The next day I took off the engine bottom cover, and noticed that coolant was dripping down the passenger side head gasket onto the oil filter, and from there had gotten blown around onto the heat shield right over the cat and made a nice black spot. After that I knew it was the head gasket, so next I checked the cylinders through the spark plug holes to make sure it was just an external leak and not seeping into the combustion chambers. I work at an auto parts and supply store, so I decided to test a product called Bar´s Head Gasket Stop Leak & Block Repair. Poured the bottle into the radiator, filled coolant up, warmed the car up and went for a test drive. After that I've done about 3500km and no more leaks whatsoever and the cooling/heating system works normally. I am about to pull the engine to do an actual complete engine rebuild with refurbished heads and new crank bearings and everything, but for the time being the stuff has really done wonders!

Do not use that, it clogged up my radioator causing it to blow

Don’t do it it totally clogged my radiator and made motor worse

sure as hell didn't work for me. You think it worked, then the first time you test drive .....No.

P0420 code is the bain of my existence! looking forward to video on it.