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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
Frustrated in Michigan
Mar 03,2021Used K-Seal to stop the heater core from leaking in my 2011 Jeep Liberty. Stopped leak in heater core but, one week later while driving vehicle the head gasket blew. Waited to get our stimulus check to have Jeep repaired. Repair shop fixed complete top end on engine and replaced the heater core. K-seal claims to not plug your cooling system. Jeep is going in for the eight time to have heater core flushed because the copper in the K-seal keeps plugging up the NEW heater core. This is what I have been dealing with. Cannot say I would recommend this product from my experience.
Mark Priebe
Mar 01,2021WORKED IN 2 MINUTES!!!...1999 Honda Civic LX...Started noticing bad gas mileage...losing coolant & engine light came on with codes for Misfire both cylinders #2 & #3...Was getting Compression pressure blowing coolant back into expansion tank reservoir & overflowing it...radiator bubbling...sure sign Head Gasket problem between cyl#2 & #3...(Be careful driving like that.. High pressure from compression from cylinders can explode radiator hose!!!)...I used Turkey Baster to remove excess coolant from expansion tank to proper level...started car...turned heat on high...removed radiator cap(be careful & let compression high pressure out slowly before fully removing radiator cap!!!).. Added 30-seconds shaken K-Seal small 8oz Blue Plastic Bottle($16.99 AutoZone)...IT SAYS PERMANENTLY SEALS HEAD GASKET LEAKS IN 1-3 MINUTES. Guess What??...By the time I plugged in OBD II Code Reader to erase engine light misfire codes....My Honda Civic motor WITHIN 2 MINUTES started running smoothly...NO MORE MISFIRE CODES & THE HEAD GASKET LEAK & MISFIRE BETWEEN CYL #2 & #3 WAS FIXED IN LESS THAN 5 MINUTES...I let it idle 15 minutes & drove it for 2 hours & IT WORKED AS ADVERTISED...NO COOLANT LEAK...NO MISFIRE CODES...ENGINE LIGHT GONE...RUNS SMOOTHLY...SAVED $$$s!!!...GREAT PRODUCT!!!...AMAZING PRODUCT!!!...WORKS EXACTLY LIKE THEY CLAIM!!!....I AM VERY VERY HAPPY CUSTOMER & WILL ALWAYS CARRY A BOTTLE IN MY CAR FOR THE UNEXPECTED COOLANT SYSTEM PROBLEM!!!
Tony Whippet
Feb 24,2021Great product, and detailed advice offered by Colin. K-Seal fixed my issue with an annoying water seepage between the block and water pump of my 1927 Whippet. The guidance provided by Colin before I purchased K-Seal was exceptional. Thank you.
Carl Davies
Feb 22,2021Blocked my heater matrix..... I poured K Seal into my coolant tank with the intention of fixing a minor drop that was forcing me to refill my coolant once every couple of weeks. Within minutes of pouring this into the reservoir, my heaters started to blow cold. I’m now forced to pay £££’s to get this sh!t flushed out of the system. I do not recommend this at all. The biggest joke is that on their website it claims it’s impossible to block such components, but horror stories all over the internet suggest otherwise. Save yourself the hassle and have the leak fixed properly. This will cost you far more in the long run.
Vera
Feb 08,2021I have just added the k seal to my water system and I was worried it didn't work so I called and got a very helpful response from the firm its been in three days now and I haven't lost a drop of water yet so I would recommend it to anyone!!! Great product and good quality no complaints at all thanks.
John Dotts
Feb 05,2021I installed a bottle of K-Seal in my 2008 Ford Focus 178K miles. I had replaced upper radiator hose about 2 years ago, and recently developed a leak in the connection of the hose to the radiator top. I 1st installed a new O ring in the end...reclipped it in place, and the leak slowed but did not stop. Once I inserted the K-Seal after about 3 drive cycles all leaking has stopped and is 100 percent perfect. I do not like the way that Ford uses the snap on with metal ring type connectors although I drive wonderful Ford vehicles. Keep up the great work and I am fully recommending your product.
Dylan
Feb 02,2021Had radiator fan go out on my 2002 galant while on a toll road and had no option but to drive home slowly but surely stoping intermediately to cool down a little. Installed replacement fan but car had been ran hot either the block got cracked or something of that nature because I noticed a small antifreeze leak but didn’t think much. It started over heating again 5 days later from lack of coolant. I filled her back up and figured once a week fill her up? I’ll live with it. But this morning I filled it up only to have every drop of coolant leak out in less than 4 hours. Never have high hopes for “fix all” products but I figured what the hey? It says one 8 oz bottle is good for a car of my size but I went all out and put 2 in just because I was so activated with the situation. To make a long story short. It sat in the driveway today running for an hour and didn’t leak A SINGLE DROP. And my heater blows hotter than it ever has. 10/10 would recommend
Stan Patterson
Jan 21,2021first off after changing my temp sensor on my dodge ram I over tighten it and ended up with a hairline crack in my manifold. So here I was freaking out and didn't have the money for the repair and thats when I discovered k-seal, or as I like to call it blue miracle it was magic ✨ in a bottle easy to use and 15 min later no leak truck running great so at least I could do is write this review to anyone reading this and is considering buying this product you won't regret it and it dose work.
Kadir Apak
Jan 20,2021Fixed my head gasket on my Lexus 2011. Best product I have ever used. No more overheating save me thousands in repair. Still driving the car with no issues. Don’t expect it to work right away. Might take a few days maybe few weeks. Keep running your car before it overheats turn off and follow again. Recommend it to everyone great product. I tried other products but nothing comes close to this
Mark
Jan 17,2021I have 1988 range rover classic with all the symptoms of a head gasket issue[ losing coolant,blowing white smoke] so i bought a bottle of kseal ultimate,but i contacted Colin first,he gave some good advice on how to use kseal,,pretty simple really i just poured it down the top hose,,i really did,nt think it was going to work,i ran it 2 days did about 100 miles and 2/3 hot cold cycles it was still blowing white smoke,,so i contacted Colin about maybe trying another bottle ,or getting a refund,,he suggested that i give it a little longer do a few more miles and try a few more hot cold cycles,ok i said..so thats what i did .Well i went to start my 32 year old rr today,and no smoke,i took for run, no smoke,i took it thru traffic,no smoke,stop start,no smoke and it ran much smoother to,i could not believe it,,so for me in my case it took approx 200 miles and 4/5 hot cold cycles before it worked..I just hope that it holds,not sure about that,all i can do is hope...Thank you kseal,and Colin.....Regards ..Mark
gary mcavoy
Jan 13,2021Overheating engine underload no heat from heaters coolant loss ( no visible external leaks) used kseal but did not fix at all not even a little, car has had a new radiator new water pump and expansion bottle also had head pressure tested
Raymond Hatala
Jan 11,2021Mechanic told me I need intake manifold gasket replaced on my 2008 Yukon Denali. I put K-seal in radiator reservoir. Let vehicle idle for 30 minutes and the Knocking noise Went away
Jan
Jan 06,2021I have a 2016 Ford Explorer that was leaking antifreeze. We are not sure but we think the leak is the water pump. To replace the water pump is costly as you have to pull the motor to get to it ($2,200). We tried k-seal, it did not work, we drove it 2 weeks still not working. So we bought a 2nd bottle it slowed the leak almost stopped it. Been driving it 1 month now and it seems to be leaking more. Should we try a 3rd bottle?
William Barnett
Jan 01,2021Kseal saved my bacon,my work van 97 dodge with 340,000 miles on it blew a head gasket on a work trip 300 miles from hime pulling my trailer. I stopped a bought kseal from a part store..,and dumped it in the radiator and in about 20 mins I was back on the road made it home no problem.t This was a year ago and to this day no problem from the gasket .thank you kseal. Wish I had more kseal for my side project but budget won't allow me too. But I would recommend kseal to anyone.i would love to have window stickers to advertise that's how much I believe I kseal..
Dean Scotford
Dec 31,2020K seal sadly didn't work for my over pressure. I tried draining off 2 ltrs first and then adding, topping up with coolant. It just spits it out, no seal and a messy engine bay.
Vokesy
Dec 15,2020Sorted a leak out in half an hour! 2004 Jeep Grand Cherokee 2.7 CRD WJ/WG (5 cyl Merc diesel engine) Low coolant light came on on a shortish journey which I checked out and topped it off with fresh HOAT antifreeze mix. A couple more journeys confirmed a leak from around the water pump. Was leaking at a rate of about 1ltr/50 miles. I couldn't see exactly where the leak was, just the general area. There was constant dripping when the engine was hot and turned off. So I hopped on the tinterweb and bought a bottle of K-seal to try. On a cold engine I dumped the contents of the bottle in the header tank and took it for a drive to get everything up to temp and ran it for a few miles after that. Checked next day and no visible leak and coolant level fine. One week later, no sign of any leak! The water pump on this vehicle is an external one driven by the serpentine belt. I would have second thoughts about using it if the pump was driven off the timing belt as you really don't want one of those to fail!
Hemi Head
Dec 15,2020Okay ! I'm convinced. I am now a loyal customer / big advocate of your product now ! I installed said product few days ago / several hundred miles (I can provide the exact date / mileage if you'd like) and the level of engine coolant has not gone down one drop, not one ! Thank You ever so much. I take very good care of all my vehicles and it was so discouraging when she started to losing coolant. My maintenance records indicate I first started to add coolant on Nov. 29, 2019 at 189,384 miles.... since then on 22 separate occasions I've had to add a combined 307 fluid ounces or 4.8 quarts !!! Not any more I'm very very pleased to report. I am 99% certain this is / was a head gasket leak from the white smoke I'd see after the vehicle was first started, again though not any more. The vehicle is a 2002 Dodge Intrepid R/T with a 3.5 liter High Output V6 24V MPI engine which as of today Friday December 11th, 2020 had 198,777 miles on it. I added the head gasket sealant by K-Seal on November 28th, 2020 with 198,348 miles. So in short its been running without any loss of engine coolant for 432 miles and two weeks. And for that I / we thank you K-Seal sincerely !!! 5 out of 5 stars !!
ROBERT FRYER
Dec 11,2020My 2007 mk1 qashqai was definitely telling me there was a problem. Strong smell of hot coolant inside the car. Nothing visible in the engine bay. Coolant level may have dropped slightly. Checked around heater area under the dashboard, especially underneath the heater matrix. Nothing visible. Concluded that it was probably a pin hole somewhere in the matrix. Would be very expensive to get the matrix renewed. Purchased K-Seal pour and go on the advice of a reputable accessory shop. Added it immediately to the warm engine and drove off. What can I say, within 5 minutes the smell of hot coolant disappeared. For me it does what it says on the tin (plastic bottle). Very very impressed as it has definitely saved me a fortune. Thankyou
ian mccrae
Dec 07,2020hi there i had problems with my car in feb,this year,,kept kept topping up water /then there would be too muh water,then low water,fan over running,,,etc,,,i put one bottle of kseal in to the water bottle and it ran great,,,,,the same problem has just started cople days ago,,,,,,,should i put another bottle of kseal in my engine?its a 2013 1600 tdci mondeo,,,,
James Damato
Mar 04,2021I had a heater core leak in my 2008 Rang Rover Supercharged. No visible leak but heavy coolant smell when the heat was on. To replace the heater core in this vehicle is a 20 hour job as you need to take the entire center dash apart, $2k job. All my rover guys said don't add any leak fix solutions as it will clog the system. My research showed K-Seal would work, I contacted Matt at the company to make sure it was safe for Rover's. He was confident it would work. Well, he was correct, it took 2 bottles and 4 days but leak fixed and heat working great!!! Great Product!! $30 repair vs $2k