I used Bars Leak in an older Ford Explorer to seal the heater core. It sealed the heater core and then some. The engine overheated and the head gasket blew. I put in more Bars leak to seal the head gasket. Well...I then had to tear down the engine to replace the head gasket. All of the water ports were completely plugged. Too much of this product is not good for an engine regardless that GM uses it. I have seen the results first hand. I ended up replacing the engine, radiator and heater core. I will NEVER buy Bars Leak again. I recommend just replacing what is broken. This gunk will not solve any problems, it just potentially clogs water passages and the cooling system in general. Way to much risk for the short lived quick fix.