K-Seal Reviews 530

My Mondeo 1.5 Ecoboost was leaking coolant and my garage concluded it was a the head gasket. I came across K seal online and having read many reviews and generally researched it it seemed worth trying. One treatment and bingo, the header tank level is not going down any more. I have done a few hundred miles now and all is still well, and I hope it will prove to be a permanent solution. I read that k seal can be left in the system, will it stay alive active if a new fault develops? If not could I add more in that situation, I would be interested to know.
This has potentially saved me a lot of money, I am keeping my fingers crossed. Thankyou k seal.

It did not seal my headgasket problem.

This did absolutely nothing for my head gasket waste of 25 bucks. The warranty is pretty much useless you want me to drive my vehicle to a mechanic with a blown head gasket so they can verify that it's leaking for $25 screw them and there's sht products

I hadn't had much luck with cars recently, my jaguar was hit and run in a car park and afterwards I had problem after problem, I bought another car which the head gasket went on the way home, a local mechanic took it to replace the engine which I'd paid for and still has it after 8 months, I bought another car to get me to work which developed brake issues, suspension issues and then started to overheat too... I had recently opened my own business so I had put all my savings into it so money for another car was an issue..... so I got car no 3 very good condition so I spent my last spare money on... it started to leak from the radiator and I was filling the water every couple of days...so I tried your product and I can safely say it worked very well and I've not had any more leak issues! I needed it to work as I couldn't afford any more garage bills or a new car.... so thank you your product saved my car and me lots of money I don't really have.

I'm sorry to say it did not work. The leak is small, I'm surprised. Can I get another bottle and try again. The leak is at the top of the radiator in the corner.

Used this product for a coolant leak. Not only didn't it fix the leak it gunked up my engine and timing chain to the point of major engine damage and repairs.

I have a 2002 Subaru Outback which blew its head gasket in November of 2023. My mechanic said the repair would be over 3000 dollars, which is frankly more than the car was worth, but said that if I didn't want to pay for the repair I could try a product like Blue Devil. After researching online I found K-Seal and decided to try it as a hail Mary to save my car. I picked up a bottle of K-Seal Ultimate and followed the instructions, and the engine stopped overheating almost immediately. It's been almost 18 months since that happened, and the car hasn't had any issues with its head gasket or coolant system ever since. The K-Seal repair has withstood daily use in a very hot climate, and allowed me to keep using the car which would have been totalled by the head gasket. It cost around 40 dollars for almost a year and a half of life added to the car, and it's some of the best money I've ever spent.

Tried Kseal numerous times with no luck. One bottle of
Blue Devil and problem solved.

Works great

Do not use K-Seal. It blocked up the heater matrix pipes in my car and the car overheated within a few minutes of starting up. Before that the car was driving fine but no heat coming from the heaters 30 mph and under. Only heat coming out at 50 mph and over. This is because the K-Seal was blocking the heater matrix pipes.

I had to have the car recovered and repaired at a garage. The garage confirmed it was the result of using K-Seal.

Yes the product will fix your car and stop leaks temporarily. However, in the long term it will damage your car and cause more problems.

K-Seal after a few months of being in the coolant system turns into a muddy/sandy type residue that blocks everything up in your car's cooling system. You have been warned.

I bought the small bottle of K seal as I was topping my radiator fluid every 2 weeks especially after a longish drive around 80 miles each way. I didn't expect too much. BUT IT WORKED GREAT. been in around 4 months no more topping up coolant. I wasn't losing coolant from radiator but I was losing it from somewhere give it a try nothing to lose ☺️

Excellent advice from Mike as I was unsure if KSeal would be compatible in a big 4L V8 performance vehicle. It worked!! An absolutely amazing outcome. So happy the big car is holding water now!!!

Very disappointed. Called them a week ago and they assured me they would get right back to me the following day with some kind of solution, understanding the dire urgency of my situation. No one called me back, so I had to just phone them again today, twice, and they are putting me off saying they will get back to me, again. Really? When?! Perhaps this honest review might get their attention. Used a half bottle of K Seal based on the recommendation of a mechanic as I could not afford a costly coolant repair, and it has ruined my car. My PSM failure light now comes on intermittently as well as the full time warning engine light being on, and my kids and I are now stranded here way out in the country where we live, an hour form the city. This is my only vehicle, and is now not drivable, and I cannot take myself to breast cancer treatments nor take my kids to swim practice, or even get to the grocery store. Thanks to this product, my situation has gone from bad to worse, and I hope they will take responsibility and pay to get my system thoroughly flushed out as I cannot afford to do so. I have since spoken to numerous mechanics as well as my local Porsche dealer and they said to never, ever use this product as it damages the system it is supposed to repair, resulting in sensor damage, clogging up the system, etc, etc...they actually warn people to never use this product and most say that they will not service any vehicle that has K Seal in it due to the numerous, mostly unfixable issues it causes to high performance cars. I am so distraught over this, I have lost sleep because I am in a dire situation without my vehicle and no money to cover what sounds like a costly and lengthy repair situation. And for history on the vehicle...I am the one and only owner of this vehicle and have maintained it perfectly for the past 18 years, and up until today it has never had any major issues. It only needed the occasional brakes, tires, oil changes, annual service, etc....so I know the complete history of my vehicle and have been the sole owner. It has been a faithful, reliable car without any major issues. And to make matters worse, the one woman who answered the phone today was aloof, dismissive, and unkind, saying there was nothing she can do about anything and I will just have to wait for them to get back to me. Seriously? RUDE!! Please K Seal, do the right thing and help me get my car flushed and drivable! How could you do this to an innocent customer?

Never let me down . Gone are the bad old days of radweld 40 yrs ago blocking pipes .
K-seal has been excellent for me and always carry a spare bottle.

I put K-Seal in my old pickup about 18 months ago and it did not work, but I chalked it up to all the junk that was in my radiator (including B...D....) fluid that had not been changed for probably 10 years. I drained the radiator, put in new antifreeze and topped it off with another bottle of K-Seal Ultimate. Instant success and I have been driving on it for almost 2 years. Couldn't be happier for what I think will be a permanent fix.

Unfortunately it did not work in my case however they did honor their refund. Thank you so much. Great customer service.

I tried it twice on my Subaru and didn't work

K-Seal clogged my heater core, which cost me hundreds of dollars and dozens of hours to get it all out of the system so I could have working heat again. K-Seal says, "The particles in our K-Seal products are very precisely designed to be large enough to repair holes up to 0.635mm in size but deliberately small enough to never block any passageways or tubes within the cooling system, including those inside the heater core and radiator." This is absolutely false. It did stop the leak as intended, but the particles were not small enough to pass through the heater core without clogging it up.

I have a 2004 Jaguar xtype that had a "mystery" coolant leak. I was told that all hoses and clamps needed to be replaced. Instead I used K-Seal once and the leak stopped immediately. What a great product!

Did my due diligence...
I have an Audi A3 Quattro 2015 and had a very minor leak from the water pump.Thermostat area, only required top-up every 4 weeks, but annoying as puddles after cold sitting, so thinking it was an expansion sealing leak.
I looked at doing it myself to replace the gaskets and is a massive job 14 hrs +... (I'm a caravan mechanic so have all the tools and able to do repairs)
So when researching I came across K-seal and read like 200 reviews and took the line, if it doesn't work ill have to replace coolant anyway...
As my leak was very minor I decided to add 1/3rd of a bottle and see what happened... So as instructed I added the liquid and ran the engine for 20 mins at idle.
The leak has now gone and not a drop since, so my thoughts are the small gasket leak was plugged easily and no leaks in the last few days.. all dry .
I will probably flush the coolant in a week so its back to usual.
I had a look at the cost to replace the water pump and gaskets and would have been $1000 (AUD) or more depending on what needed doing, so I'm happy its fixed the leak and saved me a hefty sum.
I'm aware it may need doing eventually but at this point I'm stoked it repaired the small leak with only a 3rd of a bottle...
So yes it works..