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
Andy
Oct 21,2022I'm an old man and over the years have used just about every stop leak product from "water glass" on with usually poor or horrible results. Recently my car blew a head gasket and was blowing coolant out the tailpipe. I didn't have the money to have the gaskets replaced so I tried several brands of stop leak. Nothing worked until I found K-Seal. Fixed in minutes and has stayed that way for three months. I don't know how you did it but thanks a million.
Dwayne de Lung
Oct 18,2022I don't generally buy into miracle cures but know, from experience, that some products can deliver a 'cure'. I have a 1974 Ford F600 truck that had a leaking radiator. After resoldering the tank I found there was still a 'weeping' tube in the radiator's core. A 'new old stock' radiator runs $800 - $1200 depending on the vendor so this old truck was NOT going to go that route! Did some online research into products and found that K-Seal was highly recommeded by others with older, metal tank radiators. Why not? Beats buying a radiator or having it recored, right? Let the engine warm up after siphoning off 1/2 gallon of coolant which I then added 1/2 bottle of K-Seal to (after shaking per instructions). When the radiator started steaming, I added the coolant with K-Seal mix back in and replaced the radiator cap. 1/2 hour later the radiator was dry as a bone and the engine idling happily along - makes this old guy happy to save a few dollars while not doing damage to my truck. Many thanks to the folks at K-Seal for a fine product!
Lucas Kucharski
Sep 27,2022Totally not working , just made bigger mess and foam in expansion tank , waste of money
Scott Newman
Sep 27,2022I'm sitting outside autozone with a coolant leak still I used bar's the 1st time since I have cancer and cannot afford a head gasket I'm reading all the reviews so I'm hoping this will work since I'm unable to afford much .hospital bills and life bills are tough enough so I'm really hoping this will work till I'm not able to drive anymore .I'm 33 and just really hope this will work
Jason Alan Leaver
Sep 26,2022Had a coolant leak somewhere round the back of the engine block on a 23 year old Ford Fiesta. Think it a freeze plug but could not really tell due to access restrictions. Was only leaking under pressure not dripping when engine cold. Car lost about half a litre of coolant every 100 miles so quite minor overall, and was topping up every week. Used HALF BOTTLE of pour and go in header tank, 60 miles later, coolant would previously have dropped to about halfway between min and max, but now just down 1/4. I assume some coolant still lost prior to the product making its journey from the header tank into the engine. Will be monitoring it from next top up at 100 miles, and checking every week
David Mullinax
Sep 23,2022I was pulling a 30' camper with my Hummer H2 when I started loosing antifreeze. Looks like the water pump seal was giving out on me. I stopped at AutoZone and purchased K-Seal and added it to my water reservoir and to my surprise the leak was gone in about 3 minutes! Still 4 weeks later and no leaks and no engine problems! Thank you K-Seal š David Mullinax of Ellijay Ga
Zachary Highfield
Sep 16,2022I have been in the parts sales field for over 10 years. I have seen K-seal not only seal small but also very large leaks that I thought there was no hope AND IT LASTED months to years....sometimes it outlasted the rest of the vehicle. This is the only product to buy for coolant leaks. Please never buy one of those tar/sludge sealants they will cause you more trouble down the road where K-seal just provides you with more protection down the road!
Terry O Callaghan
Sep 12,2022I used KSeal in my car a Renault Megane, Did everything according to the instructions.. absolutely useless. the car continues to lose coolant. A complete waste of money. Response to K Seal's reply. .. The symptoms are air bubbles in the expansion tank, no overheating no smoke, Followed all instructions on the bottle.. it did not work. What more can i say?
Cameron Benner
Sep 08,2022Used this on my work runner a small holden barina, to be fair I didnāt expect it to work but was pleasantly surprised hasnāt used coolant since and it has stopped mixing with the oil all though it was only a small leak I was impressed
sam Burton
Sep 06,2022I had a head gasket leak, my mechanic confirmed it. It was leaking coolant and needed to be refilled about every week and a half but the car ran and as long as I kept adding coolant it work. But with winter coming up I knew I needed to do something about the issue if i wanted to save my wallet in the future, I read k-seals sight and based on the confidence and seeing no downside purchases some. Followed instructions ran the car for 8 minutes up to operating temp, turned it off, drive it to the store, all was well, parked it. Wake up the next day, take it out get 20 miles out of the city and boom, engines hot, I step outside and see this trail of coolant behind me and Iām standing in a puddle. Pop the hood the cap blew off and the tank is EMPTY, all gone! Fillāer back up and think at least I can keep filling it. WRONG under a quarter mile down the road and I gotta stop again, luckily I didnāt get run over but the tank is pulsing up and down and spurting out coolant. Luckily though I donāt have to worry about my other leak, just an engine that has no cooling and runs for a minute at a time instead of a week and a halfā¦ After viewing said reply I have reached out and have not heard a response, will update as they come. After reaching out a second time purely about a refund I got a reply. Also instructions for k-seal bottle listed 5min ( or had no time constraint and I got the 5 min from the internet ) but even so the engine work for about an hour after adding it and it worked before adding it but after adding it stopped working.
Heather Briggs
Sep 01,2022Buy this product!! When it comes to my vehicle, I am probably the most anxious person ever. So, when I started to lose coolant at a very fast rate, have some smoking, etc. my anxiety skyrocketed. I had many of the warning signs of an impending head gasket issue. I researched what I should do, how I should fix it, and I came across K-Seal. I was skeptical to say the least at first, because I have read horror stories about how people have put sealing products in and then their engine and other vital components get gummed up and end up breaking. I reached out to an absolutely fabulous gentleman that I saw responding to reviews on this website and spoke with him via email about my vehicles symptoms, overloaded him with questions, etc. I felt confident after chatting with him that K-Seal was going to help (and at the very least not hurt) my vehicle. I followed the instructions on the package (July 2022) for adding the K-Seal and monitored my vehicle like crazy in the following days/weeks. I was nothing short of amazed when I noticed that my vehicle was actually holding coolant and all the issues I was having related to this problem before were not happening anymore! There was only one instance about a month later where I had lost a decent amount of coolant, but I believe it was related to extremely hot weather temperatures since this was the summer (August 2022) and we were going through a heat wave. Once I filled my coolant, there was no loss anymore. I had contacted the same gentleman I corresponded with and he agreed it was more than likely due to the heat, and was kind enough to send me another bottle in the mail to use in the event that I had to. I've not yet had to use it, but if I do then I am confident in putting this product in again! I have a 2005 Jeep Grand Cherokee, and it is my life. I live in the mountains so there is no public transportation, and I also own my own house cleaning business so I rely heavily on my vehicle and cannot be without it. I cannot recommend this product enough for those who have coolant/head gasket issues. If you are anxious like I was, reach out to K-Seal and talk with them first to see if this will help you - they will respond! It will help to ease your concerns, I promise you. Thank you, K-Seal, for helping me keep my vehicle running! I will recommend this product to anyone in my situation or similar! :) -Heather, from New Hampshire, USA
Gary Binks
Aug 31,2022Well nothing worse than that smell of leaking coolant in your car then the warning light and then the sodden mat in the drivers footwell. The cause was a leaking heater matrix on my Ford C Max. Top up and leaked out...garage said Ā£1,000 to fix...what?, no way. After a trawl on the net I came across this product...well time to try I thought. Followed the instructions and waited. Engine on and wait to heat, at first there was leakage but once it reached working temperature it seemed to hold. Only 75 miles in and now no leaks...Happy days and thank you, all for Ā£12.40...result. Update in a week.....
Shawn Tallman
Aug 20,2022Ok so I haven't tried the K seal yet. My 2006 Nisaan Xterra was overheating so I took it to Midas (they do all my major auto repairs) They did a compression test and it failed. šŖ Said it will be $4000 usd to repair. This is our only transportation for my family. So I'm praying this works. Stay tuned for the results. Wish me luck Colin!
Robert
Jul 27,2022My 2003 Volvo S60 was losing coolant and I was getting "Turn off engine" warnings. Whenever I turned on the A/C, the coolant would drain. I diagnosed online for what could cause this, and was seeing radiator replacements costing nearly $1,000. Fortunately for me, I came across K-Seal. So easy - I poured it into my half-full coolant reservoir and drove around for 30 minutes. Not only did my A/C run ice cold, but the coolant level remained full! Immediate results and a savings of $1,000! Based on many other reviews, I'm confident I'll get another 10,000 miles or more without any more coolant problems.
Jean Blackburn Andrews
Jul 22,2022I will admit I was a little skeptical, but this product is amazing. I have a 2004 BMW 325ci that was leaking coolant. With it being almost 19 years old I didn't want to put a ton of money into figuring out why it was leaking coolant. I bought the K-Seal Ultimate, put it in about a month ago and haven't lost 1 ounce of coolant. And my car is running better than ever!
Doug
Jul 06,2022Dear KSeal Good Afternoon! As a Commercial Pilot and Aerospace Engineer; actions speak louder then words. Recently, my 2009 Murano 3.5L AWD with 120K Miles; developed an internal Engine Coolant leak. Originally, using k&W, sealed the radiator. However; failed to repair the internal engine leak. After a two week waiting period; purchased Kseal multi purpose and followed specific instructions. Within minutes; the KSeal Performed as stated and sealed the internal leak. It has only been several days. However; the water level is being maintained. Great Job of saving me thousands in $$. Regards Capt. Doug
kev
Jul 02,2022i have a ford focus 1.0 ecoboost (eco boom) engine , just done 83k , noticed on cold start up a misfire , just thought it needed a service and new plugs as it was over due , on inspection on cold start up misfired and a puff of white smoke , did a compression test and found out cylinder one was down on compression , with these ecoboost engines apparently they are not designed to be fixed and are a throw away engine ? so thought i would try K-seal ultimate bought it off ebay popped it in and wow fair play stopped the cold misfire and no loss of coolant and no white smoke , just done an other compression test and all cylinders now read the same , i am really impressed and thanks to k seal they have save me alot ofĀ£Ā£Ā£Ā£Ā£ , thank you i would recommend it to any one
Rob
Jul 01,2022I just replaced my water pump for the first time (meaning Iāve never done it before). For a couple days after I noticed some coolant on the ground after I parked for awhile. My hunch was that the gasket wasnāt sealing properly. Instead of taking it all apart and starting over, I added a bottle of K-Seal to the expansion tank. I drove for about 45 minutes and the leak was gone. Itās now been 3 days and no leak. This stuff works!
donny Wright Still Stoked.co.uk longboards
Jun 19,2022Hi Colin, I am at GL16 7PB I have a Transit camper (ex flareside) PJI 9345 2.5L It has developed a heavy drip coolant leak from back end of engine head,so cannot see it but coolant starts appearing after engine idling 15/20 minutes from cold. No oil in leaking coolant, no water in oil, no white smoke, engine fine. Spotted it the other day with expansion tank low after a short (8 mile) journey. I presume it is a crack. Is this repairable with K-Seal and what chance of permanent success?
Mel Booth
Oct 29,2022Sorry no stars here - just used K-seal to repair leak in radiator Kia Sedona only a slight drip but no such luck for me ! need to find an other product or replace radiator. Disappointed Mel B