My car is a stock 40K mile 2000 Camaro SS that I have owned since new. I have changed the coolant many times since new but i now have this weird issue that is head scratcher for me. Before I changed my coolant last week, I noticed small pieces of what appeared to be foam floating in the coolant. It also feels like foam in your fingers. A picture of this stuff is shown below.

As such I made sure to thoroughly flush the radiator, engine block, and overflow bottle several times before I changed the coolant. Just the same the new coolant still has this stuff floating around. Are there any gaskets that the coolant touches anywhere in the system that are made of foam? I can't imagine there are but I also don't understand where this stuff could be coming from.