To leave a review you need to be logged in
If you use ULTIMATE for a Head Gasket repair and it and it fails to fix the leak get in touch to find out about our money back guarantee. For all our other brands if you have a repair that subsequently fails contact us for a replacement bottle.
Reviews 493
Morris Blanco
May 06,2024Bought a 97 Nissan 4×4... coolant would just disappear not in oil or coming out exhaust... so I tried k seal...it absolutely resolved the problem within 5 minutes... u can't go wrong with this product!
Nigel Bunn
May 05,2024Vauxhall mokka 1.6 petrol Had the car for 4 years started using coolant smell of sweet antifreeze when car was used brown gunge in coolant expansion tank and loads of water droplets on internal top surface of coolant tank Feared the worst last used k seal one month down the line gunge gone droplets gone hasn't used a drop of coolant and no smell of antifreeze Miracle in a bottle I'd say
Tom Pain
May 03,2024I bought K-Seal Ultimate about two weeks ago. After extensive familiarization with my vehicles symptoms. I had among other issues come to my comprehension why I would have the best chance of repair using the K-Seal formula that has to do with the distinctly different materials the product uses to close leaks. In my case my oil had become contaminated with coolant. I found THAT this particular K-Seal product allows you to completely ignore the fact that most all the other products with top notch reviews use glass particles, or ceramic to stop the leak. I learned that my vehicles likely problem would have made the mainstreams most popular formulas and process the mainstreams uses that are made up of GLASS fibers (ceramic) that fill in the leak and my understanding is that the type of leak I have will likely not work with that formula. I needed one that stops the leak using a formula without the glass ceramic fibers. I must use an entirely different formula and even then it will be complete "luck of the draw'. The kind and type of leak I have in the engine does not stand a very good chance at sealing using the glass fiber particles. K-SEAL Ultimate Head Gasket Repair has a does have a chance. Hopefully my No Crank No Start issue will be solved this morning and I will finally be ready to use the K-Seal. My vehicle had several problems develop that compounded to to cause my vehicle to become unusable that I had to fix before addressing the leak issue. In Short this review is only part#1. Stay tuned for my part#2 REVIEW. Now to go out and see if my vehicle will finally start so I can use the K-Seal Ultimate. Wish me luck.
Tim
May 01,2024Had a small antifreeze leak in cab of 2015 nissan frontier that appears to be from the heater core. Put one bottle into my radiator and drove truck for over 30 miles to see if it'd set. Leak seemed to stop for couple of days but now has returned as an bigger leak.
Paul Bianchi
Apr 25,2024I have a 2015 Ford Fusion SE Ecoboost with turbocharger, 92k mi. I have a very long story over past 3 months of check engine light and #4 cylinder misfire issue that couldn't be resolved. Multiple trips to the shop & diagnoses, $2k spent on new turbocharger, and check engine light still coming on. Bottom line mechanic says engine must be replaced--blown head gasket and/or cracked head. Said $9k to replace engine!! In desperation I did a lot of research on head gasket sealers, bought K-Seal, put it in yesterday, idled it 25 minutes. Drove it today. Check engine light went away!! Car runs very smoothly. I will write back in 6 months and let you know how it's going! Thanks!! May 9, 2024 Update: I haven't been able to start the car for a week. Tried various things, towed to trusted garage and verdict is I need a new engine. Now just trying to get rid of it. I'm not sure if the K-Seal failed outright, or if the existing damage was too much for K-Seal's long-term "reach". At any rate, it was worth a shot.
Jeremy Martinez
Apr 15,2024I was absolutely amazed. When the guy at O'Reilly's told me to put the bars leak back and get k seal I was hesitant but I'm glad I did. I didn't know where the leak was but I hadn't looked yet either. When I spotted the leak after pouring it in I said well that was a waste of money. It was pouring out a crack in the bottom of the radiator but to my surprise it actually sealed it. I wish I could post the videos I took
Amanda Brown
Apr 08,2024This stuff is amazing!!!! I had a small leak in my radiator and it wouldn’t hold coolant I bought this bottle of kseal and in like 5 min the leak was sealed!!! I’ve been driving a lot for 2 days and my coolant is still full and working great!!! This stuff is a true blessing I’m so thankful!!!!
Daniel Finnegan
Apr 04,2024Doesn't work !
ian butters
Apr 03,2024K seal works. Give it a go, you'll be pleased that you did. I tried it with my mechanic's approval. He said it'll work or it won't but it won't clog up anything. Guess what, it worked. My mechanic uses it all the time, with the customer's approval. Can't praise k seal enough.
Brad Ackehurst
Apr 02,2024I have an old 1977 Aussie Holden. It developed a small leak from the head gasket. My mechanic diagnosed blown head gasket. It was forming only droplets of water but it was consistent droplets developing one after another. I read reviews on multiple products, and also recalled hearing positive comments in the past on Kseal. After convincing myself that the product would not damage anything I decided to try it prior to spending significant money on a head gasket replacement. I added as per the instructions and drove for about 30 mins. Checked still a minor droplet developing. Drove for another 15 minutes,pleased to say fixed. I have waited 6 odd months prior to writing this review in case the results were short lived. However 6 months on, not leaks whatsoever. The reason I have taken the time to write the review is to share with others my successful experience. I am extremely happy and happy to recommend KSeal for like issues.
Rolf Karlstad
Mar 06,20242005 Subaru turbo blowing coolant into the zero pressure expansion tank whenever I fill the system. I'll check after the car has cooled down and the tank is completely full. Yesterday I needed to make a round trip of about 180 miles along a stretch of interstate with a speed limit of 80 mph, and I drove at that speed. Upon reaching my destination, which involved coming off the interstate and driving along some 35 to 20 mph streets, I thought I would run the engine at idle for a minute or two to let it settle down, until I looked at the coolant gauge, which was pegged high. I spent almost 3 hours away from the car, and refilled the cooling system as well as I could, and got out of town before rush hour traffic. Got home, running the heater at full blast the whole time just because. I got home okay, but the coolant reservoir overflowed again. Today I grabbed a bottle of the standard K-seal at the auto parts store, drove home, let the car cool off for about half an hour and opened the top tank. It still had enough pressure to make me use caution, but it was only air in the tank, I bled the pressure out simply by applying and reducing pressure on the top tank pressure cap. I removed coolant from the expansion tank to get the level to the "max" line. I used a baster for that, which got me just to the right level. I burped as much air out of the system as I could with the "gasketed funnel stuck into the top tank and squeeze hoses" method, which got enough to bubble out that I was happy - it's not perfect, but it was good enough. I then went for a very non-spirited drive for about 50 minutes. I tried my best to stay out of the turbo, and I used every opportunity to engine brake, presuming that it would help draw any coolant into the cylinder past what is clearly a leaking head gasket (it's an 05 subaru, it's never been rebuilt, it's a turbo -- the head gaskets leak, though there is no coolant/oil mixing) Got home, popped the hood, the expansion tank level had risen about an inch. The distance from the max line to the top of the tank is about 8 inches. It's hard to argue with the result, though I have yet to do any spirited driving. That can wait for another day. I figure I'll take it pretty easy for the next couple of days, then start giving 'er the beans and see what happens. At this time I am optimistic that it will hold up against boost, though I am not running a stock turbo or tune, and my boost is set at 19 psi or so --- yes, on an engine with stock internals with 185k miles on it, I know, I know. It needs to be rebuilt, and preferably with some stronger internals. I guess I got to rambling there, but I am trying to explain. So far I think it worked!
Emily Phillips
Mar 06,2024First, I completely forgot to shake it beforehand (rookie mistake). This was for a '93 4Runner with a badly leaking head gasket. Poured about half into the radiator, and the rest in the overfill. It took about a week I think before it fully sealed, but it did!
MR MICHAEL GREEN
Mar 03,2024Focus loosing water k seal stopped it brilliant product
LeRoy Stratton Sr.
Mar 02,2024studied different products,asked questions, said it was great product. Did used it in my 2009 Dodge Caravan. Had a small leak since brought it new. Dealer could not locate leak. So put up with it and approx., 6 months ago used it' It worked. About 2 weeks ago had heater problems, felt like thermostat. Open up the hose to remove thermostat, never seen such a mess. orange color. thermostat plugged. still not able to use vehicle.Never put that garbage in any vehicle or would recommend it. I am hoping can get it going. Also had it at garage to clean out and flush!!
Ben
Feb 22,2024I was very nervous - I found lots of positive reviews, but also plenty of negative ones. But I realised most of the negative ones were based on opinions rather than experience. I only used it as a last resort, when no leaks could be visually detected. I suspect it was the heater matrix, but wasn't going to invest time checking. But it's fixed. 10 days later still hasn't moved.
John Boss
Feb 20,2024A friend pulled up.in his 2011 ford transit t280. Coolant wasn't holding 5 litres just disappear coming out radiator etc. He checked all external.hoses which were tight. Another friend solved head gasket blown on a merc lasted another 2 years and was still running. Anyways we put stuff in, within 1 min the leak seem to have stopped. Took I for a good run a little coolant dropped. Filled it back up no leak was amazed took a fresh 5l coolant hasn't lost nothing. Engine gauge staying on 90c engines not over heating. So far so good.
Brittan Keeton
Feb 13,2024A stop leak that actually works
jim t
Feb 05,2024This product really works, I had my doubts but was proved wrong. Saved me $$$$$$$$$$
Benjamin White
Jan 23,2024My prior experience with similar products had not been good. I bought them trying to avoid an expensive fix, which I ended up paying for. There are other products that require complicated steps that I couldn’t accomplish. The KSeal just goes into the overflow reservoir and then drive to temperature. And it worked! Since added I haven’t lost a teaspoon of coolant and no more vapor trail on cool mornings. I’m ecstatic.
Keith Eppy
May 08,2024Money back guarantee yeah right I try two bottles nothing changed at all had yellow black tag on bottle said money back guarantee send them pictures what I paid for it they just left me hanging didn't back the there money back guarantee at all that's joke people don't believe the yellow black tag on bottle that mean nothing to them at all its just way get your money lot easyer they claim fake lie get people believe in junk