Liqui Moly Radiator Stop Leak | 250 ml | Cooler additive | SKU: 20132

I recently tried Liqui Moly Radiator Stop Leak in my older vehicle that had developed a small coolant leak, and I’m genuinely impressed with the results. I’ve used other stop leak products in the past, but this one stood out for its ease of use, fast action, and trusted brand quality.The instructions are straightforward—just shake well and pour it into the cooling system when the engine is warm (but not hot). Within minutes of running the engine, I noticed the coolant level stopped dropping, and the leak around the radiator seam appeared completely sealed.What I appreciate most is that it doesn’t clog the system or create sludge, which can be a problem with lower-quality products. My heater continued to work perfectly, and the engine temperature stayed normal. It’s compatible with all types of coolant, which adds to the convenience.Overall, Liqui Moly Radiator Stop Leak is a solid, trustworthy product that can extend the life of your radiator and save you from costly repairs in a pinch. Highly recommended as a temporary solution or preventative measure.

UPDATE 2.....I drive a 2015 Audi S5. It has 140k on motor. It started leaking antifreeze at 133k miles to where i had to carry a bottle of it with me and usually had to put more in every 5 to 6 days. I am at day 35.....AND THE MOLLY RADIATOR STOP LEAK HAS WORKED 100 PERCENT. I DROVE IT FROM Melbourne FL TO Jacksonville FL ABOUT 250 MILES ROUND TRIP AT APPROX 90 MPH AND THE FLUID WAS AT THE SAME LEVEL AND NO OVERHEAT ISSUES.I ALSO HAVE A REVIEW ON VALVE COVER LEAKS I WAS HAVING ISSUES AS WELL.

I like to always keep a can of this in the garage just in case. It always seals without clogging anything, as it remains liquid except for the amount it takes to seal the leak. My last repair was pretty mundane, but before that I used Liqui Moly to repair a plastic radiator that had a hairline crack on one of the end tanks. Not only did it seal the crack, it lasted two years before a different crack developed. I decided to use another bottle of Liqui Moly (I had replaced the coolant some time in between, so there was no longer any product in the system), and it worked just as before. A few months later, I was driving home when I saw steam rising and my temperature gauge steadily rising, so I pulled over. I figured that the Liqui Moly had failed at some point, but upon inspecting the radiator I found that the hose mount and most of the end tank had broken off, causing a major loss of coolant. Once the car was back home (thanks, AAA!), I further inspected the broken piece and discovered that I could see the previous cracks that the Liqui Moly had sealed within the larger broken piece - Liqui Moly was still doing its job, even though it didn't stop the giant crack from happening. And yes, I replaced the radiator at that point, along with all of the hoses and the water pump. The old pump still looked like it was in great shape and showed no sign of clogging or sealant residue, which boosted my confidence in the product. I still have that car and it still runs great, by the way. I also just recently had the timing chains done on another car, and it seems the mechanic left one of the radiator hoses loose. I tightened the clamp, which fixed the issue, but it reminded me to order another bottle of Liqui Moly to keep on hand. I know that if I ever need to use it again, it won't mess up my cooling system.

Used on a BMW 2011 E90 SULEV radiator. it had a very small leak and paying 600 for a radiator was not on my books. I normally never use additives for my car. ive had this car from new and its got over 200K miles by using good parts. i was very hesitant to use any products for this. however, liquid moly has always proven be a great reliable source for my car. i use it for my oil and such. so i have real faith this will hold and not screw up my bmw. so far the leak has ceased and the car has been running top notch.

Not enough of a leak to even see evidence of it, but enough that you can smell that tell-tale A/F smell. This stopped it for a few weeks, but it's back again now. Good thing is, this is fairly clear and doesn't pollute the coolant giving indication that it's in there.

Audi diesel EGR cooler leak, our coolant was losing most of the overflow tank in about 600 miles. Shops vary between $2K-$5K to fix this. Started using this for 2 applications so far, and it's been dramatically slowing the leak. It is not only losing halfway between the minimum and maximum line on the overflow tank in 3k miles, which is significantly less (the min max is only a small portion of hte tank)

The best thing is it worked. There was a small radiator leak in my wife's car. We would see the leaked material on concrete about the size of a half-dollar in a couple of hours. The product didn't work as fast as it claimed, but within 24 hours the leak stopped completely.