[b]It isn't the antifreeze that does the job, it's the additives. The additives are used up over a period of time, and whether used as engine coolant or engine cleaning it has to be replaced.

So in your case, T&C, try some fresh for your next try. Do not get the "Environmentally Friendly" type, along with the propylene glycol replacing the ethylene glycol it also has a much milder additive package, really doesn't work worth a rap.

Down with "Eco-Nazis!"

Bill.