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!

Water pump failed and car overheated. Repaired water pump and all went well for months. Didn’t have signs of a blown head gasket for months. Car started overheating again. No other signs of blown head gasket other than overheating. My friend looked at my car and said must be a blown head gasket. I took it to a shop and they wanted $4k+ for repairs. Yea not worth it for my car. At least not right now. So he said to buy this and see if it works. Boom. Put it in the system and followed instructions. Added the whole bottle for my two and a half gallon coolant system. Let it sit and run and sure enough the heater started working again and he said it’s working. Let it sit and run for another 30 mins to make sure. Didn’t overheat. So I decided to stress drive it and drove it for 2 hours and didn’t over heat. Yes this may be a TEMPORARY FIX, but if it lasts me a six months to a year than I will be grateful. Just need the time to learn how to change a head gasket safely on my own so I can actually repair it. Might take me months for actual repair,it’s a big job for a newbie. I’m no mechanic plus I work 60 hrs a week. If it gives out again , I just may try this again. For less than $50 to fix the car temporarily, sounds like a good deal in my opinion. Btw, after researching, I heard it could last a few years and tens of thousands of miles.

This product worked wonders for my vehicle had a terrible leak in the exhaust port of the head with white smoke coming from the car bad I put this stuff in and it fixed it quickly but it sadly didn't last but a month because a pulley when out and the car overheated and the leak started agin

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.

There's a 50/50 chance it works. Its hard to know if it will work because this works on leaks upto a certain size and theres no real way of knowing how large the leak is until the engine is taken apart. I must say I had a very small leak that was causing misfires, starting issues and draining the coolant tank empty about every week. I used this product and it completely solved the leak, misfire and starting issue. Alternatively, I've used it on other vehicles and had no success. If you dont have money for the large repair bills it's worth the gamble to try this first as a last resort.

Had a head gasket leak in my engine for my 2003 Dodge Durango. Had lots of white smoke out of the exhaust. I had my doubts about this stuff working but the cost of replacing the gaskets is very expensive. So thought I would give it try. I followed the instructions to the key and watched a real good YouTube video on it. When I fished my first drive, the smoking stopped and I've not had any trouble since. Have put about 3,000 miles on it since and hauled several trailer loads of woods. May go out on the next drive, but holding up so far. Would recommend the try.