i recently added a bottle of "antifreeze stop leak" to my car. now i checked the antifreeze a few days later and i see that the antifreeze in the radiator has a thicker consistency than it should be. the fluid in the over flow tank is thin, just like normal antifreeze. do u think it thickened up because of the stop leak stuff? (i'm assuming thats how it stops the leak but i'm not sure) is this something to worry about?