Wynn's Radiator Stop-Leak - Seals Radiator & Head Gasket Leaks - Prevents Corrosion & Rust - Compatible with All Coolants/Antifreeze & OAT Fluids - Safe for Hoses & Sensors - 325ml

My car started leaking water from the cooling system, it slowly got worse yet we couldn't work out where it was leaking. I was having to top up my coolant every 2-3 days. Even my local garage said it's going to have to get worse before we can see where it's leaking!! Decided to buy some of this as the reviews were good, poured it in the radiator, drove it around 5 miles, no more leaks!! This has been in my car around 3 or 4 months now and still not had to top up my water. Fantastic stuff, will 100% recommend this product as it's solved my water leak. Obviously for major leaks or split hoses etc this will not be suitable.

I had a really small leak from my coolant system, but enough that I had to top up coolant every other day. I used this and it's cured it amazingly. Really great stuff.

I tried what i thought was the best on (K Seal) which didn't work. then i tried this stuff, miles better, worked a treat. If i need to stop a small leak now this is the stuff i would buy again.

Certainly stopped my water leak

So far I am very impressed, honestly thought this was a load of rubbish. I poured the whole bottle into the coolant tank and it seems to of completely stopped my coolant leak. Lets see how long it lasts. Max coolant temp is now 105 When driving motorway drops to 80-90 Good result. Update my corsa has started leaking again, but the leak is minor. Still a good temporary product in my opinion. I also used this on my smart roadster brabus and the leak has stopped for now and the temperature is good.

Not sure as some review are mixed review, not sure if instruction were not followed properly... It says at back of bottle that to [warm up the engine with heater control in HOT position] ... meaning, this is BEFORE pouring the additive. Its not clear what is the warm amount. Some car (old) can heat up high temperature in few minutes compared to newer cars. Do not take any risks to open coolant cap as it may be dangerous. Second part it says [add the contents to the cooling system: via the expansion tank if part of the system circuit (2 hoses: out and return), or directly into the radiator of a single hose overflow tank is fitted.] .. WTF lol, i lost it, didnt bother and returned it.

After losing water for some time now I have decided to try this after seeing mixed reviews. I can honestly say that this has stopped the leak . It's only been a couple of days since i have used it and have noticed the coolant hasn't moved at all. I will obviously keep an eye on it, if anything changes I will report it on here, but for the time being all is good.

Unable to use as intended as fluids not low enough...