K-Seal Reviews

I’m blown away. Kept my vehicle from ending up in the junkyard. Totally recommend it.

This is the worst product I've ever used. They say it doesn't cause any harm, but that's total nonsense! It messed up my brand new radiator that I just replaced a few months back. My mechanic warned me that this stuff can really ruin your radiator. Good luck if you decide to try it!

Truly outstanding, it surely earns a five-star rating. Functions perfectly with my 2006 Ford Fiesta Ghia 1.6. No problems at all, and those pesky leaks are gone!

Seriously, steer clear of this stuff. It clumps up and messes with your engine. I added it to my coolant overflow tank to fix a slow leak, since I was using up a gallon of antifreeze every month. Now, those clumped bits are blocking my smaller passages and making coolant spew out from the bottom radiator hose. I'm now burning through a gallon of coolant each week. Even after swapping out the thermostat, water pump, and return coolant hose, plus flushing the system multiple times, I still find these pea-sized bits of kseal hanging around. If anyone's got tips on how to remove this without shelling out a fortune, hit me up.

This product is top-notch. It eliminated the annoying 'weezing' noise from the heater core in my vehicle. I'm always impressed by items like this that help avoid a visit to the mechanic.

I own a 2006 Volkswagen Beetle, and I tried using three bottles of your product to fix my water pump. Unfortunately, it didn’t seal, and now my car is stranded on the highway. I followed the instructions and thought it would work since it claims to be guaranteed. I was under the impression that if it didn’t work, you would replace the bottles, but it seems like that’s not the case. It’s frustrating because the label clearly states that if it fails, you’ll replace it. Now, it feels like you’re not honoring that promise. I plan to share my experience on other platforms regarding this issue and the lack of guarantee. I’m also wondering how to get in touch with customer service, as I haven’t received any guidance on that front. The website hasn’t been helpful either.

This thing just didn’t do the job. There was a leak coming from the freeze plug behind the flywheel, and it was a pretty serious one. I figured I’d give it a shot anyway. I let the engine idle for an hour, but it’s still leaking.

I was also losing around 2 pints of antifreeze every time I drove. Even after taking off the pressurized surge tank, I couldn’t spot any leaks. There was a bit of white vapor coming from the tailpipe, so I figured it might be a head gasket or intake manifold issue, leaking into the power cylinder. Plus, I was getting a spark plug code for the #1 cylinder. I checked out various reviews for sealers and went with K-seal. After sticking to the instructions, my antifreeze problem vanished and the engine code cleared up. K-seal truly does the job!

My mechanic was unable to detect any leaks in my coolant system, yet the coolant tank was emptying daily! I reached out to K-Seal via email to see if they thought their product could help in my case and received a reply in less than an hour. Talk about great customer service! Like many folks, I had my doubts about K-Seal but decided to give it a shot the next day and, to my surprise and delight, the issue was fixed. No more leaks from the coolant tank! I'm really pleased with both the product and the support. Definitely recommend it.

I gotta say, K-seal has really saved me a ton of cash. It totally fixed my head gasket issue. I feel super fortunate to have found this product. You can definitely use it without any worries. Plus, the way customer service handled everything was top-notch. They were incredibly helpful in making sure everything went off without a hitch. Huge thanks!

My 2006 Ford Ranger was leaking coolant right when I started the engine, coming from the timing cover. I followed the instructions on the K-seal 8 oz bottle, and it’s been five days now with no leaks at all! This stuff really did the trick for me and saved me a bunch of cash on repairs. Much appreciated!!!

I can't believe it actually did the trick! My vehicle had a coolant leak that was bubbling out. The mechanic thought the head gasket might be cracked, letting gases leak out. They quoted me a whopping £1000 for the fix! After some digging around, I stumbled upon K-Seal! Amazingly, just one dose in the coolant tank and it did the job! Huge thanks! You saved me a ton of cash!

So, my 2014 Chevy Cruz was leaking from the water pump. I checked out some reviews and watched a bunch of YouTube clips, and decided to give it a shot. Huge thanks to whoever put those instructions out there! In just about 15 minutes, the leak was gone. Next week, I'm planning to tackle another car of mine that’s got the same problem.

I’m not typically one to share reviews or trust a ‘stop leak’ solution. I had a leak in my engine block that seemed to be oozing from the middle of a freeze plug. Getting to it was a real hassle without removing the motor, so I decided to give your product a shot, and I’m blown away by how effective it was. Can't speak to the long-term effects, but I’m really pleased at the moment. Appreciate a product that actually delivers on its promises!

Hey Colin,
I’m really excited to see all these great reviews, so I’m planning to grab a bottle tomorrow after work.
I’ve been topping off my coolant weekly for about 3 to 4 weeks now, roughly 1 to 1.5 quarts each week. My engine runs cool on the highway (around 150-170°F, but it should be at 200°).
However, when I’m in traffic or at red lights, it starts to overheat, then suddenly drops back to a cold temperature.
I thought it was the thermostat, so I replaced it, but that didn’t change anything.
At first, I didn’t see any leaks, but then I discovered a tiny pinhole leak in the radiator. It seems to only leak when the car builds pressure while driving, not when it’s parked and off.
Since the coolant loss is minimal, I doubt it’s enough to cause such a drastic temperature spike. So, I’m starting to worry there might be a head gasket problem. I’ll try the KSeal and let you know how it goes by the end of the week. Thanks a lot!

Oh, and just so you know, my ride is a 2006 Chevy Impala with a 3.4L 6-cylinder engine.