[Oldtruckfanatic]

A couple of things here. First off all that stuff is good for is plugging up radiators and heater cores. Secondly and this part is important...if you have coolant leaking externally you MIGHT get it to stop with sealant however if you have compression leaking into the coolant passages you may as well not waste your time. I get an average of about 3 cars per month that have hydrocarbons in the coolant and excessive pressure or venting of the degas bottle or radiator cap. Just about all of them pour that garbage in the cooling system trying to solve the problem and all of them that follow through with the correct repair usually end up replacing the radiator and or heater core in the following months even when I try to flush the system after repair. None of that stuff will flow into a void that has compression blowing out of it and what does manage to get in during engine off periods is blown right back out when the vehicle is started again. Theres just nothing to keep it in there. That stuff works under the premise that the solids will fill a void under pressure and build up and that pressure will help keep it in place after the void is filled. It was never meant to fill a void that has pressure coming from the other direction. Simply put. It wont work.