K-Seal Avis 

I have a 2015 Ford Fusion SE Ecoboost with turbocharger, 92k mi.
I have a very long story over past 3 months of check engine light and #4 cylinder misfire issue that couldn't be resolved. Multiple trips to the shop & diagnoses, $2k spent on new turbocharger, and check engine light still coming on. Bottom line mechanic says engine must be replaced--blown head gasket and/or cracked head. Said $9k to replace engine!!
In desperation I did a lot of research on head gasket sealers, bought K-Seal, put it in yesterday, idled it 25 minutes.
Drove it today. Check engine light went away!! Car runs very smoothly. I will write back in 6 months and let you know how it's going! Thanks!!

May 9, 2024 Update: I haven't been able to start the car for a week. Tried various things, towed to trusted garage and verdict is I need a new engine. Now just trying to get rid of it. I'm not sure if the K-Seal failed outright, or if the existing damage was too much for K-Seal's long-term "reach". At any rate, it was worth a shot.

I was absolutely amazed. When the guy at O'Reilly's told me to put the bars leak back and get k seal I was hesitant but I'm glad I did. I didn't know where the leak was but I hadn't looked yet either. When I spotted the leak after pouring it in I said well that was a waste of money. It was pouring out a crack in the bottom of the radiator but to my surprise it actually sealed it. I wish I could post the videos I took

This stuff is amazing!!!! I had a small leak in my radiator and it wouldn’t hold coolant I bought this bottle of kseal and in like 5 min the leak was sealed!!! I’ve been driving a lot for 2 days and my coolant is still full and working great!!! This stuff is a true blessing I’m so thankful!!!!

K seal works. Give it a go, you'll be pleased that you did. I tried it with my mechanic's approval. He said it'll work or it won't but it won't clog up anything. Guess what, it worked. My mechanic uses it all the time, with the customer's approval. Can't praise k seal enough.

I have an old 1977 Aussie Holden. It developed a small leak from the head gasket. My mechanic diagnosed blown head gasket. It was forming only droplets of water but it was consistent droplets developing one after another. I read reviews on multiple products, and also recalled hearing positive comments in the past on Kseal. After convincing myself that the product would not damage anything I decided to try it prior to spending significant money on a head gasket replacement. I added as per the instructions and drove for about 30 mins. Checked still a minor droplet developing. Drove for another 15 minutes,pleased to say fixed. I have waited 6 odd months prior to writing this review in case the results were short lived. However 6 months on, not leaks whatsoever. The reason I have taken the time to write the review is to share with others my successful experience. I am extremely happy and happy to recommend KSeal for like issues.

2005 Subaru turbo blowing coolant into the zero pressure expansion tank whenever I fill the system. I'll check after the car has cooled down and the tank is completely full.

Yesterday I needed to make a round trip of about 180 miles along a stretch of interstate with a speed limit of 80 mph, and I drove at that speed.

Upon reaching my destination, which involved coming off the interstate and driving along some 35 to 20 mph streets, I thought I would run the engine at idle for a minute or two to let it settle down, until I looked at the coolant gauge, which was pegged high.

I spent almost 3 hours away from the car, and refilled the cooling system as well as I could, and got out of town before rush hour traffic. Got home, running the heater at full blast the whole time just because. I got home okay, but the coolant reservoir overflowed again.

Today I grabbed a bottle of the standard K-seal at the auto parts store, drove home, let the car cool off for about half an hour and opened the top tank. It still had enough pressure to make me use caution, but it was only air in the tank, I bled the pressure out simply by applying and reducing pressure on the top tank pressure cap.

I removed coolant from the expansion tank to get the level to the "max" line. I used a baster for that, which got me just to the right level.

I burped as much air out of the system as I could with the "gasketed funnel stuck into the top tank and squeeze hoses" method, which got enough to bubble out that I was happy - it's not perfect, but it was good enough.

I then went for a very non-spirited drive for about 50 minutes. I tried my best to stay out of the turbo, and I used every opportunity to engine brake, presuming that it would help draw any coolant into the cylinder past what is clearly a leaking head gasket (it's an 05 subaru, it's never been rebuilt, it's a turbo -- the head gaskets leak, though there is no coolant/oil mixing)

Got home, popped the hood, the expansion tank level had risen about an inch. The distance from the max line to the top of the tank is about 8 inches.

It's hard to argue with the result, though I have yet to do any spirited driving. That can wait for another day. I figure I'll take it pretty easy for the next couple of days, then start giving 'er the beans and see what happens.

At this time I am optimistic that it will hold up against boost, though I am not running a stock turbo or tune, and my boost is set at 19 psi or so --- yes, on an engine with stock internals with 185k miles on it, I know, I know. It needs to be rebuilt, and preferably with some stronger internals.

I guess I got to rambling there, but I am trying to explain. So far I think it worked!

First, I completely forgot to shake it beforehand (rookie mistake). This was for a '93 4Runner with a badly leaking head gasket. Poured about half into the radiator, and the rest in the overfill. It took about a week I think before it fully sealed, but it did!

Focus loosing water k seal stopped it brilliant product

studied different products,asked questions, said it was great product. Did used it in my 2009 Dodge Caravan. Had a small leak since brought it new. Dealer could not locate leak. So put up with it and approx., 6 months ago used it' It worked. About 2 weeks ago had heater problems, felt like thermostat. Open up the hose to remove thermostat, never seen such a mess. orange color. thermostat plugged. still not able to use vehicle.Never put that garbage in any vehicle or would recommend it. I am hoping can get it going. Also had it at garage to clean out and flush!!

I was very nervous - I found lots of positive reviews, but also plenty of negative ones. But I realised most of the negative ones were based on opinions rather than experience. I only used it as a last resort, when no leaks could be visually detected. I suspect it was the heater matrix, but wasn't going to invest time checking.
But it's fixed. 10 days later still hasn't moved.

A friend pulled up.in his 2011 ford transit t280. Coolant wasn't holding 5 litres just disappear coming out radiator etc. He checked all external.hoses which were tight.

Another friend solved head gasket blown on a merc lasted another 2 years and was still running.

Anyways we put stuff in, within 1 min the leak seem to have stopped. Took I for a good run a little coolant dropped.

Filled it back up no leak was amazed took a fresh 5l coolant hasn't lost nothing. Engine gauge staying on 90c engines not over heating. So far so good.

This product really works, I had my doubts but was proved wrong. Saved me $$$$$$$$$$

My prior experience with similar products had not been good. I bought them trying to avoid an expensive fix, which I ended up paying for. There are other products that require complicated steps that I couldn’t accomplish. The KSeal just goes into the overflow reservoir and then drive to temperature. And it worked! Since added I haven’t lost a teaspoon of coolant and no more vapor trail on cool mornings. I’m ecstatic.

Just used a bottle of HD! Always the same result and response from truck owner! Coolant absolutely running out of a radiator, due to the part being curbed heavily. Low truck or mental driver!? I like to get as much heat in the Coolant as possible as I was always told it aids repair. No time really on this occasion, just bunged it in the header. Driver looks on with pessimistic grin. About 1 minute in and a wee trickle was left but it soon dried up after another 30s. I always enjoy just sticking a bottle of coppery stuff in and sitting back to keep me in a job one more day! Also watching the disbelief in the onlookers. Sometimes it's not that dramatic but I have never been let down by this sealant. Again there's a limit to its powers, if you attend a breakdown where you have to search for pieces of Coolant system and engine block I'd save the bottle for another day. As for clogging up tight areas, I worked for JCB. The 444 engine, we were told, had so little tolerance for Coolant transfer that any sealant wouldn't be possible. I tried it on a test engine in our workshop and had no issues at all. However, I'm only speaking from personal experience and I went steady as I poured. Anyway I'm a fan and will continue to enjoy using K-Seal. I always recommend it to people in the trade.

I have used this product successfully on a previous occasion to plug a leaking radiator on my Vauxhall Zafira with half a bottle. I am now losing coolant and engine oil through a suspected head gasket leak and an additional full bottle has not cured it this time around.

Used the head gasket sealer bought from a motor factor and it didn't work despite using a qualified mechanic who recommended it

I read the advice on the bottle I went to your website clicking the link got me nowhere as once clicked on the union jack for uk nothing happened
Try it yourself

Manifold gasket, 2001 dekota, when I applied it at first it worked for about two weeks, check engine light came on. Took it to the shop they told me it was two gaskets, add another bottle. Check engine went off, haven’t had a problem in about a month now. It works, I’ll keep u updated

Originally purchased k-seal ultimate to fix a potential head gasket leak, gave the stuff a chance to work some magic and it improved the Performance and issues with my vehicle, not 100%.

I got in contact with the customer care team, very quick to response and very helpful, quickly sorted me another bottle to hopefully fully fix the problem.

I would recommend this product to anyone who may have a potential head gasket issue before paying out £1000s even as a temporary fix. It has not caused any clogging issues with my car either.