Pontiac Repair: sludge/grit in radiator, grand prix gtp, gm dealership

Question
97 grand prix GTP 3800 super charged--4 years ago flushed radiator at GM dealership due to brown sludge/grime in radiator (80K miles). brown fluid is starting to get thick/grimey again (112K miles). what can be done to prevent? should dealership change or should I get one of those "kits" to flush? Any indication of potential engine problems?

Answer
Hi John:

Yes this is a problem! If it's not addressed it will effect the cooling system in the car. You can dfo it your self with a prestone flush kit. Use there super flush it's a 2 part cooling system cleaner and neutralizer. The issue is a chemical reaction between the antifreeze and the water and a system that was low on coolant. for some reason some areas that have hard water and the dex cool don't mix well. and if the system is low on coolant and air is induced into the system the reaction happens. but the cooling system flush and follow the directions to a "T" then add fresh dex cool at a 50/50 mix with water and keep an eye on the system to make sure it doesn't get low if there is a leak in the system fix it and I would recomned that you change the antifreeze again next year. once these have this issue it's hard to get it all out of the engine,radaitor and heater core. good luck :)