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

This product worked great at removing my system rust. This poor car was run for awhile on straight water and rusted up badly. After changing the coolant a couple times and still having an overheating problem, I tried this out to see if it'd help and I must say it did! I drained the radiator and filled it with Theromocure and distilled water. I then drove it to work for a couple days and man did the coolant change! The bottle on the left was what I started with and the 2nd one on was after the Evapo-Rust. It turned BLACK as night and smelled like dead fish! All in all it was in the system about 4 days and driven 3. To finish the flush I drained the radiator (with a cool engine) and took out the thermostat to speed the process. I filled it with more distilled water for another 10x cycles of running it for about a minute, flushing it and repeating. Now my system is super clean and ready for upgrades! I even took a drive on the current coolant/antifreeze and ran it hard to see if it'd would overheat in 100 deg F outside temps and was very pleased to see the needle never moved above normal. I highly recommend this product!

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.

This product is absolutely amazing, and it works just as described. I had been suffering from overheating. I have tried several flushes with no good results, and I constantly have rust in my block due to the previous owner running straight water for an unspecific amount of time. But now, with one evaporation treatment, there is no longer rust in my block, my radiator, or my overflow tank anywhere. I would highly recommend you buy this product and utilize it.

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.

Fantastic product! Used on my 1998 Ford F150. Inherited this vehicle, never serviced. I followed the directions. It took 3 complete flushes to remove the contaminants. Worth the effort and time!

I used this on a 1987 Toyota MR2 that has Sat a lot and despite being flushed a few times over the years, it had heavy iron/rust deposits in the entire system. This product works. I honestly didn't expect it to as the most powerful acid flush I could buy did touch the rust, but this did an amazing job. I still have some residual rust, so I'm using the product a second time to really get the system clean. This car had an 1/8" of rust built up in the inside of all the rubber hoses and this product is dissolving it. One use got most of it. Do not hesitate to use this, but make sure you flush your system to water before you add this product.....

I recently bought a low mileage super clean 97 F150. The owner took great care of everything except the cooling system. The truck ran great and had no cooling issues, but the coolant was filthy!. I did several full system flushes to no avail. It kept puking up dirt and debris. I tried a Prestsone Superflush and followed directions - still filthy after several more full flushes. Found this stuff - ordered two bottles. Ran it for 6 hrs of driving. Wow, coolant was black and stunk as others have noted. Gross! Pulled the thermostat (rust gone and clean passages! So I started the flushing process again. It took somewhere around another 12-14 full flushes with some driving (heat cycles) to get all the crud out. I was worried that the heater core may have been weakened by corrosion and fail, but whew I got lucky! Anyway this stuff really works. It cleaned out all the rust and crud where the other stuff failed miserably. This whole fiasco took about a month, 500 gal hose water and 50 gal distilled water get the cooling system back to normal.