PrestoneAS105 Total Cooling System Cleaner for Radiator, Heater Core, and Hoses, 22 oz., 6 pack

I've used this in the past and it always did a great job. Old antifreeze has a bad habit of corroding the internals of an engine and cause damage you may never see.Hint: If you buy a flush kit to do the entire job you must also take the thermostat out to flush the motor, if you don't then all you are doing is flushing the heater coil and not the engine. Here's the right way, buy this stuff, pour it in, drive around for a day or two and let it cycle into the engine and water pump along with the heater core. Remove the thermostat (good time to replace it since you have it out) put the connector back on without a thermostat. open up the bottom drain on the radiator and take off the cap, turn on the water hose and start your engine and watch it till all water is perfectly clean (around 5 minutes should be enough, more if you want) turn off water,close flush kit with cap, install new thermostat and close drains on radiator making sure the radiator has completely drained. Refill with new 50/50 antifreeze till full, check it later or the next day and top off as needed.

I dont like prestone but this is citri acid. A diluted foush at 100k in distilled water then let it sit overnight cleans well. Not ideal for some vehicles that say otherwise but most if not a regular thing would do alright. I stress diluted in distilled water. People who hype how it cleared garbage when they dumped in in coolant are morons. Mix any random garbage with your coolant and you create a sludge. Drain the radiator and flush with distilled water until drain fluid clear. Then use this. Then flush several kore times with distilled sonthis doesn't get left behind and mix with the new coolant.

This product cleaned out my coolant system well. I had to use two separate cleaning to get it thoroughly cleaned out. It also kept my engine operable in the Florida heat for several days.

I used this flush over the summer to clean out my coolant system. My coolant was pretty clean as it was so I was just using the flush as a preventative measure. I used as directed and refilled with fresh coolant. No issues and no complaints.

My V10 truck has a high capacity cooling system, so two bottles required for Clean/Flush. Balance to my supply cabinet for the “family fleet”.