Bar's Leaks HG-1 HEAD SEAL Blown Head Gasket Repair

I have a 2007 Toyota FJ Cruiser, this review is going to be detailed with my problems and solutions. Just know as of today (9/6/25) My Fj is running great with no problems after using the Head Gasket Sealer (put in my vehicle on 7/21/25). *** Jan. 22, 2025 (OD 241030) - My FJ out of the blue started to have a rough start and 4 warning light came on. It was pulling code P0306B Cylinder #6 misfire. The mechanic said I needed a Tune Up, so we replaced the Sparkplugs and did an oil change. Problem stopped. *** Feb. 27, 2025 (OD 241893) - Really rough start, engine shaking, stopped after 1 minute, drove to work. The Engine seamed to pulse, like it was having a problem with fuel. While driving home 4 warning lights came on, then the engine light started blinking. The whole car started shaking, and I was unable to drive faster than 30mph. FJ was in "Limp mode." Had it towed to the mechanic the next day, where it started just fine, no lights, no shaking - NOTHING. Mechanic drove it for 3 days, and NOTHING. So when I got it back, I went to the desert, drove in 4x4 for 8 hours - NOTHING. Did 80mph all the way up the HWY 8 Grade (SanDiego) - NOTHING. At this point I think my FJ is possessed! *** all of March - no Problems! *** April 1, 2025 (OD 243193) - The rough start and shaking is back, drove it straight to the mechanics. Pulled codes P0306 and C1201. "Pressure check cooling system for possible blown head gasket and inspect cylinders. Wire borescope found #6 cylinder getting coolant inside cylinder, possible head gasket, need to remove heads to inspect." SOOO after being told it was a possible head gasket, and being quoted almost $5000 to fix it, I went to a new Mechanic. *** During this time, the Warning lights would turn on and off, some days it would start just fine, some days it would shake like crazy. I never saw a decrease in Gas milage, or white smoke from exhaust. *** April 24, 2025 - Finally dropped off for inspection by new Mechanic. He didn't think it was the head Gasket, after telling him the symptoms. Lights were on, pulled code P0306. The new mechanic, pulled the fuel injectors one was corroded. Swapped that out, cleared codes. Warning lights stayed off for about 2 weeks. Then would come on for a day, then shut off for a week. Some rough starts mixed in. *** June 4, 2025 (OD 244033) - Added coolant to radiator reservoir. Lights keep going on and off. Took it back to the mechanic, still pulling code P0306 and we decided that yes it had to be a blown Head gasket and that it would be better if the engine was replaced. He looked for a new engine, that was going to be $5000 plus labor. I decided to wait a little, and went out of town. *** July 14, 2025 (OD 244722) - Lights came on and stayed on. I spoke with another mechanic and he mentioned a head gasket sealer. That is when I started to research different products and came across "Bar's Leaks HG-1 HEAD SEAL Blown Head Gasket Repair." My FJ seemed like a perfect vehicle to try it on, it wasn't over heating, there was no white smoke, it was using a lot of coolant, it started fine most days. So I ordered it up! What's the harm in trying something for $35, the worst thing that will happen is I will have to replace my engine (which I already need to do). If I can fix the problem for $35 and get another 10-15k miles on my FJ, I will try it! *** July 21, 2025 (OD 244918) - TODAY WAS THE DAY! I read the directions 3 times to make sure I did it correctly, I wanted to make sure that it worked and I got the best result I could. I will say that I did need to drain some coolant from my radiator, as it was too full to add half a bottle of the Sealer. So here goes nothing! Put the Sealer in, Started my FJ, Turned the AC off, and the Heater on HIGH. It took about 40 minutes for it to get to temp. Turned it off and let it cool for almost 2 hours. Started it back up and did a 15 minute lite drive keeping the RPM's between 1500-2000. Cleared the codes and shut it off. Turned it on the next day, No lights, No shaking, No smoke, no weird sounds - NOTHING. Did it work!?? I think so (fingers crossed)!!! *** Sept 6, 2025 (OD 245875) - I have driven almost 1000, I have gone 80+mph, driven for over 2 hours straight - and everything seems totally fine!!! As of today, I will say IT WORKED PERFECTLY! It looks like a $35 fix, just saved me over $5000 and that is amazing! If something changes, I will update my review. But right now, I recommend this product to anyone that has a high milage car with a blown head gasket. It really does work and it works well!

The head gasket blew on my 1997 Ford F150 and was leaking antifreeze into the spark plug wells of the Triton engine causing the spark plugs to short out and making the engine run rough. I first drained the old radiator fluid out and ran Prestone radiator flush with fresh coolant in the system for three days of driving to clean out any gunk. I wanted my system as clean as possible so this stuff would stick. I drained the system again and then I mixed this product into some more brand new radiator fluid. I took the truck for a short 15 minute drive AND LET IT COOL DOWN over night as per the instructions. I then took my air compressor and blew the water out of each spark plug well. After my next drive when the engine cooled I again blew out each spark plug well and this time there was NO WATER AT ALL in any of the wells! The truck ran great, and I was able to drive it with no problems. Once every week or two I would blow out the spark plug wells to see if they continued to stay dry. For a couple of years I had no leaks. After that time when I blew out the spark plug wells I always had a small amount of water in one or two wells. I figured the product just stopped working. But then the thought finally came to my mind one day that perhaps there was no more product left in the radiator fluid because it was all used up sealing up leaks. So I bought another bottle, drained the radiator fluid out of the truck, and mixed in the new bottle with fresh radiator fluid. That was it! The leaks stopped. This time it lasted for about six months and then I started having water in the spark plug wells again, so I repeated the process with another bottle and fresh radiator fluid. Again, the leaks stopped. So the problem is the head gasket is continuing to deteriorate, but by putting a fresh bottle of this stuff in the radiator whenever it starts leaking again that solves the problem. That makes sense. There's only so much product available in the water and when that's used up there is none left to continue sealing whenever new leaks develop. New leaks are developing because the head gasket is continuing to deteriorate as the truck and engine get older. So my strategy is to continue repeating this process simply by replacing the radiator fluid and adding a new bottle of this product until I decide to have the heads rebuilt or replace the engine. This is the CHEAPEST and best way to go right now, and it keeps my truck running and usable. The engine now has 280,000 miles on it and does not burn or leak any oil. I religiously change the oil and filter every 3000 miles and I don’t abuse the engine. Since the head gasket first started leaking I have been able to keep my truck running for 4-1/2 years now using this “Head Seal Blown Head Gasket Repair” product. My truck is old, but I love it! I will give it a new paint job and keep driving it. I'm not too wild on spending $80,000 for a new truck that has a shorter bed with limited load capacity and all this computerized crap with a hundred sensors that spies on me and rats me out to whoever wants to pay for that data. I don’t want a truck that decides whether I’m fit to drive or not and listens to everything I say and reports that to whoever wants to snoop on me. This stuff lets you keep an older vehicle running and saves you money. In my book, these guys at Bar’s Products who developed this ARE PURE GENIUSES! They rock!

I was nervous about using this product based off of the reviews that claimed that it didn't work for them but it worked for me. My father and I followed the instructions to the T and the stuff worked. We had taken the car (a 2004 Toyota 4Runner) to a mechanic which properly diagnosed the problem as a leak in the head gasket. We got the estimate of $3,000 and decided to try this before actually paying that hefty sum. The check engine light came on with a misfire in cylinder six, we had battled problems with this car and that light for the better part of this year and the problem at first was a faulty fuel injector, which was fixed, then we needed a new radiator, which was also fixed. Both parts did indeed need replacing upon our own inspection because it is a good rule of thumb to ask for the replaced parts from a mechanic. I am guessing that the old radiator was not working properly, therefore not cooling like it should, and eventually causing the leak. It is important to fix the symptom causing the leak and not the leak itself first. If we had dumped this stuff in without fixing the radiator, it probably wouldn't have worked. Try this product after exhausting all other options. The check engine light went off after 3 days and my radiator no longer needs to be topped off after driving. Ease your car into a normal driving routine, run it in the driveway for 15 minutes gently, then take it for a spin around the block, let it cool, try it again, then take it on the highway but don't take it over 60-65 mph, let it cool, try it again and this time really test your car. I went over 80 to really make sure the leak sealed and the next day the engine light was gone and a week later my car is still back to it's old self. We ended up pouring HALF of the bottle, which was probably what ended up working because our cooling system had a capacity that was just above the cutoff for half bottle but we opted for a half bottle anyway. All of that being said, caution should still be exercised because not everyone has had success with this product. My top takeaways to make sure this product has a chance to work for you are these: 1. Get a head gasket leak properly diagnosed by a mechanic 2. Fix any underlying problems first or rule these problems out, such as the radiator or any other problem in the cooling system. 3. Cool your car overnight and follow the instructions, don't assume you need the whole bottle because you may not, plus you get another shot at it if it doesn't work the first time but hopefully it shouldn't come to that. 4. Ease your car back into a driving routine and give the stuff a chance to work, if you can help it, find a large stretch of highway that you can cruise control on and steadily expose your car to a higher workload each day over a 2-3 day period. The only reason I say this is because the heat in your engine and cooling system activates the molecules in the sealant and slowly ramping up the workload exposes the sealant to different temperatures at different times. Thank you for reading and good luck!

UPDATE: No more than two weeks after writing the review below, I got a check engine light with a Cylinder 1 Misfire on the OBD. I cleared it, and a few days later it came back on. This pattern repeated for about two weeks, and it became clear that it was time to let my baby go. I think my 100 mile drive to San Diego and back was what put the final nail in the coffin. So in summery, yes, this stuff works temporarily, especially if your car hasn't been overheating and you're driving less than 30 miles at a time. It probably would hold indefinitely if you're only commuting and not transporting a heavy load. It really is a finger-in-the-dike solution, and it won't hold for long under stress. It got me through two months which was long enough for me to drive down memory lane and say goodbye to my old truck and replace her with her baby sister, just like that episode of the Wonder Years when Jack Arnold (the dad) has to replace the family car. I wasn't disappointed by the outcome but took a star off my original score, just so my review is not any more misleading than it may have been. Is it worth buying? It was for me, but if you're less sentimental and you'd rather tare the bandage off than peal it, I would go directly to replacing a high mileage car or the head gasket. Good luck! Please read on for the original review: ORIGINAL: Crossing my fingers as I write this, but it seems to have done the trick! I took my 2005 Tacoma into a local auto garage after the first time the Check Engine Light came on in late May. Mechanic said it was my thermostat, so he replaced the part, and I was on my way $400 later. Check engine light came back on June 20th, and by this time I had purchased an OBD II bluetooth scanner and Torque Pro for my Android device, as I felt powerless with my last experience. It showed a cylinder 1 misfire, and figured I needed new spark plugs so I went on Amazon to purchase new spark plugs, a spark plug wrench socket, anti cease compound and a torque wrench to do the repair myself (it was kinda fun!). I cleared the check engine light, and drove normal until July 6ish, when the check engine light came back on with the dreaded cylinder 1 misfire. From then on, I kept clearing the light and checking to see how long it took for it to come back on; it seemed to happen every 5 or so days and always when the engine was cold, and I was speeding up from 0 to 45 mph, as I live right off a busy street. Took the truck to the dealership on August 1st for a diagnosis, and they told me that I had a minor blown head gasket, which was leaking coolant into my cylinder 1 causing the misfire when the engine was cold. They can tell because, they checked the spark plug for wetness after leaving the engine off over night. As the engine heats up, the misfires stops because the gasket expands and creates a seal. They used the scare tactic to tell me that I will need a new gasket or I would need to sell the truck within a few weeks because the engine will soon start over heating, leaving me stranded on the side of the road. The repair would cost $2500, which include the gasket inspection of the head for cracks, machining the head, and obviously reassembly. Check out the photo attached the recommendation. I got super depressed that I would have to give my baby up soon, as she and I have gone through so much together, so I started to research the problem and came across this Head Seal and a similar product from another brand. After watching a few testimonials on YouTube, I decided to give it a shot. Being a total beginner in auto mechanics, I didn't understand how to drain the coolant properly, so I made a mess, but got the Head Seal liquid in and ran the engine as instructed on August 4th. I kept my eye on my OBD with my android tablet almost every day, and found a cylinder 1 misfire "pending" in the app five days later on August 9th. My check engine light came back on the next day on August 10th, and I got depressed again. I cleared it and kept driving, as I started to shop for a new truck. Well, it's September 6th almost a month since the last misfire, and there hasn't been a new one. I keep the tablet in the truck most of the time to run diagnostics, and still nothing. Here's my theory: Because I only had a slight leak, the nano particles took a few heating and cooling cycles to really get in the cracks and cure into place. Therefore, it's a slow process, especially for an intermittent leak like mine. I try not to rev my engine over 2500 rpms, and drive slow while it heats, which probably helps too. So far so good! I keep my tablet in the car to keep an eye on the thermometer as well, and the coolant stays at about 88 degrees Celsius when driving on the freeway, which is perfect. As soon as I see an uptick of one or two degrees, I'll flush my coolant. I've gone on several 100+ mile trips also in the last month, and it's holding up. It's been a roller coaster ride (not the product, but my experience with my truck) but I'm glad things are stable. Will update if anything pops up in the next few weeks, but it looks like this seriously saved me $2460, at least for the time being. Knock on wood. If you're having these issues, good luck, and may the force be with you!

I talked to a Bar's leak tech rep before using this and followed his recommendation to flush the cooling system completely before adding half a bottle to my 2.5L 2006 Subaru forester engine which had bubbles in the cooling reservoir, was loosing antifreeze, and obviously had a blown head gasket. It was not overheating after their recommended test of 20 minutes, in fact it would take three for four hours before it lost enough antifreeze to overheat. I added the HG-1 per his recommendation and followed the directions to a tee. It initially cleared up the white smoke coming from the tail pipe but didn't stop the bubbles in the reservoir or loss of antifreeze. After about a week, I spoke to another tech rep who recommended that I drain the cooling system, refill with a second application of Bar's Leak HG-1 and follow the instructions again which I did. I've been driving it for about a month now and I still have the problem along with a lot of gray gunk in my cooling system. I called a Bar's leak tech rep again (April 2020) and he did not have any other ideas except to say that it doesn't work on all engines but that they would send me my money back or send me another bottle of HG-1. the only hitch was that I needed to get a statement from a repair shop that the car still needed a head gasket replacement. This is an example of a worthless warranty. If I take it to a shop it will cost me at least $100 to get such a statement and I only paid about $34 for the HG-1. The car is old enough that putting $2K or $3K into a head gasket replacement is not worth it so I am just going to live with the problem and fill up the radiator when it needs it. Based on my experience, don't count on this product to fix your head gasket problem despite all the positive reviews out there. I thought I did my homework by reading these but was totally misled. This is not the cure that is 'guaranteed' on the box cover. You will just waste your money.

Please read the whole review. I own a 2000 Pontiac Firebird 3.8 l V6. I bought it unknowingly having a head gasket leak. It got to the point to where coolant was leaking into the oil. I couldn't even go driving without coming back and half of my coolant was gone. I bought this because I didn't feel like taking apart the whole engine and thought it was worth a shot. This product worked perfectly when we first put it in. There's a noticeable change in the exhaust sound like it was sealing up. for the first few days coolant did go down a little bit but not as much as it used to and it got to the point to where the coolant would stay all the way at the top. There is still bubbles in the oil for a little bit. So I went for a long drive and took the oil cap off to let all the water evaporate from the system. I just got back from driving and there is no more bubbles on the oil cap which indicates The gasket has been fixed. Definitely worth it! I have been driving aggressively for the entire time I put this in the system. It's a manual so that's expected and it has not failed me. So if you own a 2000 Pontiac Firebird that's a V6 and you have a head gasket leak. I would definitely recommend you trying this out UPDATE: the head gasket sealant is fine for temporal use. If you just need it to work for a little bit it's fine. But for bigger leaks it doesn't work very good. Car ran fine for about 2 months and then the leak came back and it was worse I tried one more bottle just in case but eventually I had to take the engine apart and just do the head gaskets myself. I've seen it work better for others but for me it just wasn't very good. It's worth a shot I would say, but you might just need to replace your head gasket.

So I hadnt the infamous 2010 Prius death rattle in the morning or on cold starts. I had a small leak and coolant would enter the cylinder. This fixed it almost immediately. After driving for 20 minutes next time I started the car it was gone. It’s been a week and it hasn’t came back. So far so good👍🏼

I've waited 7 months to do this review because I wanted to be sure. I took a gamble and it paid off big time. I took my 1999 Lincoln Navigator to firestone and received an $1700.00 labor cost for the replacement of a radiator which had two small holes and to replace lower head gasket which had a minor leak. I didn't want to spend that kind of money at that time because it would have ruined Christmas for my kids. Therefore, I decided to try an alternative which was Bars leaks and I have to admit that this stuff actually works. Since i have a very large radiator, I purchased two bottles and used 1 and 1/2 of bars leaks sealant to get the job done. If you want it to work properly, use the amount that is needed for your size radiator. If you come up short, more than likely it wont work. Spending $120.00 dollars for two bottles is better than spending thousands. Now there is a down side i experienced with this product which another customer wrote about which i believe is correct. The product clogged up my heater coil. The heat did not get too hot during the winter, but I managed. Im not complaining, just explain. The sacrifice was well worth it because my kids enjoyed their Christmas, and i saved a tremendous amount of money for what i thought was a temporary fix - but instead 7 months later its still working so its a permanent fix. Oh, almost forgot, i had my radiator flushed out three times in January along with the heating core which did provide a tremendous amount of heat for a couple of days then went out again. The reason im sharing that with you all is so that you see that my radiator and gasket still hasn't leaked in about 54 months after i had bars leaks flushed out. This stuff has actually bonded stronger than a regular thin gasket just as they advertised. Listen, I am a regular consumer just like the rest of you, and have no reason to lie for this company - but if you have a leak that's not ridiculously large and you want it fixed, I recommend you buy this product. Follow the instructions and be sure YOU HAVE ENOUGH TO TREAT YOUR RADIATOR and I can guarantee, you cannot go wrong. Again, I have a 1999 Lincoln navigator which has one of the biggest engines and radiators. If this product can fix my car, I don't see why it cant fix yours.

I have a Ford fiesta 1.4tdci 2010 2nd owner, from the time I brought the car it always had coolant loss don't where changed the head the piston 3 times and then also same problem 4th time got the half engine done new block piston seal still face the same problem over heating and coolant loss was fed up of putting in so much money and could not take it for a long ride but after putting this it's been a more then a week and the engine noise changed in 15 mins and all the noise from the engine just went away and till now its holding coolant and not over heating anymore will update if I face any problems in coming times but for now it works

It works

Funciona perfectamente, altamente recomendado

Simple to use and has fixed the leak for now. Appears to be working.

This product will not fix every head gasket issue, but it was able to fix my 2016 Prius head gasket 100%. The car was blowing white smoke out of the tailpipe and I had to top up the coolant every 2 to 3 days. I dumped half of the bottle in the reservoir tank, drove the car normally for a couple of days and the smoke disappeared. This was 2 months and 2,000 kms ago. Definitely worth trying before taking the engine apart.