K-Seal Avis 

I am not one who usually writes reviews. But this product blew me away.

when my car was about 6 months old, the check engine light came on, I took it to the dealer, and they found no leaks, but the coolant was low (the code was for the water pump overrevving)
They added coolant and sent me on my way.

6 months later, the light was on again, took it in, and the same issue, they decided that my intake gasket was the culprit, they replaced it and sent me on my way.

2 years later the light came on again, and now I am out of warranty, so I had to pay for a diagnostic, they found the head gasket was blown, and 2k later I was on my way.

A year later, the same issue, this time they want to charge me 3k to tear the engine down, then there will be extra charges once they find the problem, so I purchased a case of coolant, and every 2-3 weeks I was about a half gallon low, I used up my case of coolant, so I went to the part store to buy another case, the friendly guy at Autozone asked me why I need so much coolant, I explained that my car has a slow leak and it will cost around 4k to fix it.

He told me about K-Seal and said that he swears by this product and it's worth a try, he also told me about the warranty you guys offer.

Well, I didn't trust it, so I bought a case of coolant (I was a half-gallon low) but decided to give it a shot.

It's now been 6 months, and my car is right at the full line when cold.

I don't know what magic this is, but I am recommending that everyone carries a bottle in the glove box.

Thank you for making this awesome product, you saved me thousands and the headache of not having a car for weeks.

and if you know someone that wants to buy 5.5 gallons of coolant, please send them my way :)

Follow up: 1 year and 40,000 miles later and my coolant is still full

2006 Ford ranger leaking coolant on engine start up from the timing cover. Followed directions on the K-seal 8 oz bottle and it’s been 5 days and not a drop leaking!!! This product worked for me and saved me $$$ on repairs. Thanks!!!!

Shocked it actually worked! My car was having a coolant leak bubbling over the top. Mechanic suspected the head gasket had a split causing gases to escape. I was quoted £1000 for the repair! After doing some research I found K-Seal! Unbelievably one application into the coolant reservoir and it worked! Thank you so much! Saving me so much money!

My 2014 chevy cruz had the water pump leaking I read reviews and watched YouTube videos and tried it, thank you so much I followed the instructions and within 15 mins the car had stopped leaking , next week I am going to try it on another car of mine with the same issue

I’m not one to write reviews or believe in a “stop leak” product. I had a leak in my block that looked like it was coming out of the center of a freeze plug. There was no easy way to get to it without pulling the motor, so I tried your product and am amazed how well it worked. Don’t know long term but I couldn’t be happier now. Thanks for a product that does what it says

Hi Colin-
I'm thrilled to read all these excellent reviews, I am planning on buying a bottle tomorrow after work.
Been topping off weekly now for 3 or 4 weeks. About 1-1.5 qts a week. Engine runs cold on highway (about 150-170°F, should be 200°)
yet when off highway in traffic,red lights,etc. it starts to overheat, then will drop to cold temp again.
I was convinced it was thermostat, replaced it but no effect.
No visible leakage(at 1st) but then found tiny pinhole leak in radiator. I think it is only discharging when car builds pressure during driving but not when parked and off.
Because it is a small amount of coolant loss I do not believe it would be enough to make it spike in temp that severely. Thus, I am starting to fear there may be a head gasket issue. I will use the KSeal and report back at the end of the week. Thank you

By the way, my car is 2006 Chevy Impala. 3.4L 6 cyl

Best chemical ever made worth money
Works 100 %
Blessings

My car Mercedes GL63 amg 2015
I have a water leaking from the upper tank, and I think it's the head gasket. There is no white smoke no hot engine no mixing of water and oil
I bought K-Seal from amazon and I followed the instructions behind the package i put one bottle in the coolant system but it's didn't stop leaking!!
Note: Ihave changed the radiator, the water pump, the thermostat and the tank cover.
Is there any other advice?
If i put two bottles does it work to stop leaking?

1987 Chevrolet R-30 Dually
Engine: 5.7L(350) TBI (cast iron block and heads)
Mileage: 390,000 total / 44,000 since major overhaul
Problem: Had to add 1-2 pints coolant to reservoir after two heat/cool cycles and bubbles in coolant reservoir when the engine is running.
I have owned this truck 33 yrs.
I have read at least 100 reviews of K-SEAL and have not seen a vehicle this old with a coolant loss problem. When I had the engine overhauled the machine shop crack-checked the heads and reported no cracks found. At about 30,000 miles since overhaul I changed the water pump. Being an older truck it uses the Green coolant. After changing the water pump I topped-up the radiator and reservoir with DEXCOOL. [I found out later that mixing the Green coolant and DEXCOOL is not good!!] Checked the radiator about 10,000 miles later and there was reddish/brown sludge/jelly in it. I pulled the heads and took them to the machine shop to be cleaned and checked(the machine shop said no cracks were found). While the heads were off I flushed the block, radiator and heater core. I installed the heads with new head and intake gaskets. I don't know if a head is cracked or the block is cracked or a leaking gasket. The only symptom is coolant loss in reservoir and bubbling in reservoir while the engine is running. No vapor at tail pipe. I consulted K-SEAL tech support and K-SEAL ST-3501 was recommended. I began the process with a cold engine. I removed (5) quarts of coolant from the radiator. I shook the K-SEAL product for 5 minutes. I wanted to be sure it was mixed good. I poured the product in a clean (1) gallon jug and filled it the rest of the way with fresh Green coolant. I serviced the coolant tank with fresh coolant. I started the engine and let it run for 5 minutes. I shook the jug of coolant and K-SEAL mix then poured it slowly into the radiator while the engine was running. I replaced the cap and let the engine idle for 45 minutes. I shut the engine down and let it sit until the next afternoon. I ran the engine again at idle for 30 minutes. Later that day I drove the truck about 30 miles. The next morning I checked the reservoir level- NO COOLANT LOSS!!!! Since then, I have driven the truck about 200 miles consisting of 15 heat/cool cycles. Still no coolant loss in reservoir!!! I have not drained and flushed the radiator/engine since adding the K-Seal. Heater works great. If you have a similar problem like mine, before you act call K-SEAL tech and consult with them. Follow their instructions exactly. I know this is a very long review but I wanted to give as much info to maybe help someone keep their truck on the road.
I recommend this product
UPDATE: 1/16/2023. K-SEAL repair still working after
2,000 mi. and over 60 heat/cool cycles! I am very pleased with this product and the customer support.

So i purchase a 2013 bmw 328 never will buy a 4 cylinder engine i didn’t know what i was thinking ,when all the cars that i have purchase prior were all 6 cylinder , so i made a call to K-seal back in july so i went to the pep boy so i brought the K-seal Ultimate i was having grey smoke coming out the and the engine would sound like a jet engine i took the car to the shop they said my Gasket need to be change they told me to sale the car i was like only using this car to drive local area sense i have the x6 as back up now its November 21 2022 days before thanksgiving i start three day in the row no smoke and when i start the car the engine is quiet im amaze with this product it works like a champ the reason it took so long for me like said i don’t take it out of state like that i give it a 5 star you just have to be patience with it

I recently had a leak from my radiator. I looked on Amazon for a top selling radiator repair like stop leak. I found K-Seal and gave it a try. It stopped the leak. I highly recommend it. Thank you K-Seal!

Had a leaking heater matrix and loosing coolant and windows fogging up and smell of coolant.. been over 10k and this k seal bottle is a absolutely amazing thing very highly recommended.. doesn't loose coolant.. no smell of coolant inside car and when heaters on windows are not fogging..

What can I say had a leak or crack in my radiator used k seal and it totally repaired so grateful worked for me 😂

Used it on my 2013 Ford Focus SE but took @ 20 minutes before it stopped the leak. Next morning I found dripping again on the driveway and it got worse, so I went again to the store and bought another 8 oz bottle and put it inside reservoir tank as per instructions, thinking this will reinforce but nothing happened, leak got very bad as I drove the car. After calling Customer Service number for help (609-261 4242) someone named Max or Matt said won’t honor any warranty or refund as advertised just because I added two bottles of the product to the car. From now on, every time I am at an auto parts store and see someone attempting to buy this product, will let them know about my very disappointing experience with this product and with the answer of their so called “customer service”

Sorry 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

I'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.

I 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!

Totally not working , just made bigger mess and foam in expansion tank , waste of money

I'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

Had 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