Thermocure Coolant System Rust Remover, 32 Oz, Rust Remover for Vehicle Cooling Systems, Removes Rust Scale and Deposits

This product really works. Fought with a plugged heater core for over 5 years, tried everything, I was going to pull the dash to change the heater core and tried this as a last ditch effort. It worked! Saved me a lot of work. Amazing product. Highley recomend.

I have an older low mileage van where it appears that the cooling system just didn't get the regular attention a van with more miles and use might. This thing was probably stored for long periods of time. When I first bought it, it appeared to run hot at higher speeds but after some diagnostics the thermostat was determined to be the culprit. I looked into the radiator and it was an ugly rust brown mess. Several normal, no chemical additive flushes later the running hot problem still existed. At this point changing the thermostat probably helps but the corrosion in the cooling fluid, while it can be drained out, corrosion and scale would still be present on the heat exchange surfaces in the engine block, radiator and likely the now gunked up thermostat. Changing the thermostat without first treating the inner surfaces of the cooling system would only partially solve the problem. In this particular model of engine, a thermostat swap would also be a 3-5 hour ordeal - expensive. Enter Thermocure, and here are the caveats. Use it as directed but know that you will have to do more flushes to totally clean out the Thermocure. I did 6-7 post-Thermocure process before I started seeing clear water. What this stuff get out of your compromised cooling system is miraculous. On maintenance issues if I'm told to do it every 5000 miles, I do it every 3k. That's just me. I did the Thermocure flush twice, I used two containers, flushed a total of probably 10 times in all. But the interior of the cooling system is far cleaner, the van runs nice and cool, tak w longer to come up to operating temperature, and you can physically see the thermostat, now cleaned out, coming in and out depending on the stress applied to the engine. Before you use it, understand your vehicle's Hester core and why you have to run the heat in order to fully flush out your system. This stuff WORKS but know that you should probably take an extra step or two to get the best out of it. Simply adding some and draining the solution is only going part of the way. Add Thermocure, run engine for several hours, leave it in a few days, flush out solution, repeat, repeat several more times, repeat a couple more times in the interest of being thorough. This stuff works well and has saved me hundreds of dollars.

A few years back, the heater core on my 2002 S10 got plugged up. I took a gamble, disconnected it, and blasted it out with a garden hose. It worked—for a while. But within a year, it clogged again. I flushed it again and realized if it was getting that gunked up that fast, I should probably take a look at the rest of the cooling system. Sure enough, the coolant looked like rusty-orangey vomit. I drained everything, filled it with distilled water, ran it, flushed, and repeated. And every time, the water came out black and chunky. It was gross—and frustrating. After five full distilled water flushes and trying a few different chemical flushes, I still wasn’t seeing clear results. The gunk just kept coming. Then I came across this product. I added it to the radiator, ran the truck for a few days, and when I drained it—holy hell—it was nastier than ever. But after that? My flushes finally started running clear. I did a final rinse, refilled with new coolant, and now the S10 is running like new again. Bottom line: this stuff works. Yeah, it’s a bit pricier than other flushes, but it actually did the job—first try. Super easy to use too. Just pull out some coolant, pour this in, run the engine a few days, and boom—radiator clean as a whistle.

I added this product in my system, and after the first day, a freeze plug dislodged from my engine block. Fortunately the plug was replaced without major engine work. Really wish that didn't happen because there's some rusting in my coolant system, but now I'm too paranoid to add anything other than coolant. The amount of time this product was in the system, it did appear to remove a good amount of rust.

Used this on a 1997 land cruiser that had a pretty rusty system. Really did exceed my expectations after running it for around 200 miles following a head gasket job.

The truck heater seems to be working again. A good flush. Some time with this product sitting in the core. All seems much better now

Found about this stuff from an Internet forum. Cleans the corrosion out of engine coolant passages. Highly recommend for classic cars!

I recently bought a car that ended up having a ton of rust in the cooling system. Even bleeding the cooling system of air and removing the thermostat, the car ran warmer than normal on the freeway. I removed most of the coolant and ran this with water, and within a couple of days I already started seeing temperatures that I was expecting to see without a thermostat (car having a hard time keeping operating temperature on the freeway, runs cold). Opening the radiator cap to check, there is plenty of loosened rust that the flush got. Works as advertised!