calcium buildup in block?

[ashford]

when it gets warmer outside(above 80) i notice my car lacking power and some detonation. after its been shut off for awhile the temp actually rises about 20 degrees. thinking i got a bad rust or calcium buildup. i contemplated draining the coolant completely and running upto walmart and getting about a gallon of CLR but dont know how good that is on seals, so i was just asking if there is any chemical additive safe for runnig in the coolant system to eat off corrosion and buildup.

 

[Pakrat]

I use the Zerex brand, avaliable pretty much anywhere. They make a really good flush product and follow up with the anti corrosion and water pump lubricator before refilling the system.

 

[bull999999]

Prestone sells bottles of flushing compounds that you can use. Also, make sure that you use distilled water instead of tap water.