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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
Hayden Byers
Mar 02,2020I can’t believe this worked on my 2008 Honda Pilot!! I was so stressed out today after my engine kept overheating. I noticed my coolant was out and kept re-filling it, only to find it was leaking out. I also was having heat issues, so I suspected something wrong with the heater core. My mom mentioned this product to me so I tried it right away and OMG it worked!! My engine temp has been stabilized for over 2 hours driving around now. THANK YOU.
L Witten
Mar 01,2020I have a 98 gmc jimmy that is slowly leaking from the water pump. Will this product stop that? Im trying to making replacing the pump a last resort.
Don O’Neal
Feb 21,2020We received a sample of the K-Seal product after seeing it at the O'Reilly Auto Parts Show. Just so happened, the same day it showed up we had a work truck with a leaky water pump. Read the instructions, used just as instructed....... BOOM No more water leak. Great product that we are looking to find more opportunities to prove how excellent K-Seal performs. Thank you, Don O'Neal
Mehrez
Feb 13,2020This product is very dangerous nearly blow up my engine blocked all my radiator and damage thermostat cost me nearly £300 fixing my car don't use it Yes I been in contact with you'd and I give you the number on k seal botl you asked for and I did tel you rac told me that what caused damage and my thermostat damaged my reciept I asked europart for copie coz they got my details but they sed we don't keep details on computer The K seal botl have reference number and I did give u the referance number that the proof of the product clearly
Gareth
Feb 10,2020Had a water leak on my Saab under acceleration, emailed Colin to find out if K-seal was the product for me and he gave me some top notch information specifically for my problem so I gave it a go and I've noticed almost immediately it fixed my problems. I've left it a couple of weeks to write this review to make sure it has worked. I've had a few school runs and a trip to hull and back for an operation and the Saab now doesn't use a drop of water. Really impressed with the whole experience from the initial email to Colin to the results. I won't struggle recommending K-seal to anyobe. 10/10
James Moy
Feb 05,2020Would anyone recommend K seal for a twingo. My coolant is playing up. It's last resort
Jamey Colin Hodgin
Jan 28,2020tried this as a last resort and I must say, I'm cautiously impressed. It stopped my head gasket leak almost instantly. it's been three days now and the heat is still working good as new. no more pressurizing the coolant out of my expansion tank, no more constant overheating. a word of advice,,drain your radiator half way then mix the kseal with the coolant that was removed,,then add back into radiator. do not pour kseal by itself directly in! have the car on an incline and start the engine and let idle for a good half hour, then take it on a light drive. i had to add a bit of coolant the next morning but since then the level has held in my radiator..bravo kseal. Edit. Colin it was a 2002 Hyundai Elantra, 105,000 k. 21 days now and runs good as new. Edit: 5/12/21. 16 months now and holding strong. Zero issues.
Pieter Marchant
Jan 25,2020Owning a 2003 Rover Connoisseur (2.5 V6), I have been plagued with what appears to be a common problem with this model ... adding even the smallest amount of stop-leak to the cooling system will block the heater matrix! Believe me, I've tried them all - from stop-leak with rubber bits to stop-leak with aluminium filings to all impressive (not) magic potions that promise the world but fail on delivery. Topping up the radiator became a regular annoying occurrence. Believing there had to be a solution to this problem, and not wishing to strip down the engine to fix a small water leak (which appeared to be coming from the inlet manifold - another known issue on this model) I tried one more time to search the internet for the solution. By chance I came across K-Seal. The reviews appeared good, but I'd come across similar before. Reviews can't always be believed. I contacted Colin at K-Seal UK and asked his advice. Not really expecting a reply (been there, done that), I was surprised to receive a very prompt response explaining, in detail, how I might overcome the problem. Wow! 10/10 for customer service. Following his advise, and to my amazement, the leak was fixed almost instantly. Furthermore, the heater was still working perfectly. There had to be a catch, right? So I left it for a few days ... then a few days more ... then I took a long trip into the country ,,, but, despite my efforts, I was unable to disprove K-Seal's promises. This product really did work! K-Seal is an amazing product and I have no hesitation in recommending it. If you have tried other stop-leaks which have failed, don't let that influence your decision with K-Seal. I don't know what the magic potion is, but it works ... brilliantly. Colin and the team at K-Seal have in-depth knowledge of their product and, from my experience, are more than willing to help with advice - something not often seen these days.
Mark Mackenzie
Jan 24,2020I brought kseal ultimate head gask, as had head gas leak on my bmw series 3 . I used on my car as instructive, this work fine for around 20 mins then started to over heat again and leak has come back.. so I’m pretty disappointed in the fact that I’ve lost my money and the item didn’t work .
Tony
Jan 24,2020[update: Colin had arranged another bottle of K-Seal to be mailed to me, together with a page of additional instructions. It apparently worked after the second try - there has been no leaking for the past 10 days. This time I idled for more than 30 minutes. Hopefully the fix is permanently. The rating is upgraded accordingly.] I think I need to share the strange but overall negative experience with K-Seal. I bought a bottle of K-seal pour & go early this month from Amazon to fix a small coolant leak which was detected in the annual inspection. I poured the thing into the coolant tank as instructed about two weeks ago. There was no tangible effect in the subsequent about one week, and I continued to observe small leaks. As I don't drive the car often, I thought I could wait for some time to see if K-seal could work. Then I suddenly found significantly bigger leaks several days ago. I refilled coolant and tried to have my car checked out by mechanics, but could not do that due to scheduling problems in the weekend. Then by Monday or Tuesday, I found there was almost no leak at all. As I thought K seal might finally worked, I found significant leak (and in more places) again on Wednesday and Thursday (today). Now I am sure K seal won't work on my car and I will need to have the leaking fixed at an auto shop. I gave two star instead of one star because I really had low expectation for K seal to fix the leaking. How it works as described sounds a bit magic to me. [Not sure how to respond to you right here, Colin. I will try to write to you privately.] [Sent a message to cbenzie @ kseal.com 6 days ago - no response as of today.]
Thilo
Jan 18,2020Customer from Australia !! Used this for a small head gasket leak. Worked for a few days before issue coming back again. Pretty sure more quantity would’ve done the job but it’s not viable to get another of this as competitors price have more quantity.
BodyBuilding over 40 Team Botello
Jan 16,2020Ease of use 5 stars, I read instructions and decided on less is more and ran it on 2oz. to start and Wow all cleared up. Amazing Product I thought all I saw on YouTube was fake until I tried it I AM A BELIEVER.I must add my Head was not cracked so I think this helps manly just a rear part of gasket on an E39 BMW, On first application it was smoking I guess settling the product in place then all of a sudden it STOPPED COLD. Water loss ZERO. I was utterly amazed. I still have roughly 6oz of product left, I'm a firm believer in less is more attitude just put enough to get job DONE. I also must add I'm not a firm believer in additive product this is the first time in about 19yrs of me owning this car I've done this, I have had this car going on 20yrs yes I do love it and I will get the head-gasket repaired but for the Money and I spent on product it is well worth it. I would recommend this product to anyone in an emergency situation or someone needing to patch it up to reach a mechanic. I know it says Permanent fix but I will also get work done why Cause like I said I'm not an additive kind a guy and believe in the patch but the fix will give me a better peace of mind.
Pete Klar
Jan 07,2020Worked first time and now 12 months on still all good
clare
Dec 31,2019Did not work on my astra mk4 waste of time and money, still hear water gussing around at the back of dashboard when revving and lots of white smoke....
Garry
Dec 29,2019I had a leak at the bottom of my radiator last winter and this stuff really did work within a few minutes and stopped the leak completely. The problem is the leak just started up again roughly a year later. Not sure if I should try another bottle of K-Seal and see if it fixes the problem for good this time or not. UPDATE: I'm changing my review from 3 stars to 4 stars. This is due to the excellent customer service I received. I was sent a free bottle of K-Seal very quickly (a few days after I sent the email). I used it on my vehicle and the following day the leak stopped. If the seal lasts this time it will be a 5 star product for me.
Jared Davis
Dec 25,2019stopped my coolant from leaking, also stopped it from getting to the engine. an overheated broke down truck is no fun in a Minnesota winter
David
Dec 20,2019The heater matrix was leaking on my car filling the inside with the horrid smell of hot anti-freeze. Not good when the car is used as a taxi. After reading several reviews on here about heater matrix getting blocked after using K-Seal I was a bit worried so I contacted Colin who replies to the reviews on here. Colin assured me that K-Seal cannot block the heater and a cold heater its almost certainly caused by an airlock in the system. I followed Colin's instructions and gave it a go. He said to warm the car up, drain off some of the coolant and mix this with the K-Seal before pouring it in the radiator expansion tank and then taking the car for a long drive with the heater on full. The result was no more smelly car and still got full heat. Now after more than 1000 miles I still have full heat from the heater and no smell. So 5 stars for K-Seal. Has saved a fortune compared to a new heater matrix.
Adrian Hutchings
Dec 17,2019I used k seal ulitmate for a blow head gasket about 3 years ago The first bottle worked about 5 days. I rang k seal customer services They were so helpful &suggested a second bottle which they sent for free . The second bottle worked & have lasted about 3 years. very good stuff . And the customer service is excellent & help me every time I rang for advice Many thanks
Philip Cotton
Dec 17,20192015 Toyota Avensis D4D Taxi 150K. Last year was losing 1-2 litres a week with no obvious leaks, all tests pointed to head gasket which was replaced costing £1500. All good for 8 months when same symptoms started again after forking out £10 and following instructions my coolant loss has stopped with no adverse reactions. Perhaps if I'd tried it first I'd be better off by £1500 and wouldn't have been in the garage for 2 weeks. K Seal was added 5 weeks ago and car has been in constant daily use since then, cant reccomend it enough.
John P. Kuchta, Jr.
Mar 04,2020I was dumb struck when a Google search for a "pipe leak repair kit" yielded an entry on K-Seal. Yes, my leaking head gasket on my Chevy Duramax Diesel has been malfunctioning for three years, but the leak was becoming more of a problem. The first bottle of K-Seal didn't do the trick, perhaps due to simply dumping the contents in my coolant reservoir tank; but, I unclamped the radiator hose for a second bottle of K-Seal and tilted the hose to allow as much K-Seal as possible to flow directly to the engine. I'm here to testify that the second bottle did the trick. I've been running around town on the Interstate and in traffic and I haven't lost any coolant for the first time in three years! Total cost of K-Seal was $75.00 versus the $6,600.00 quote to replace the head gasket at a local Chevy dealership. A mechanic friend of mine confirmed that he replaces head gaskets on Fords all the time for just about that price! God bless Melissa and her boss for bringing such a great product to the marketplace!