I have a 2008 Toyota Auris. Yesterday I was stuck in traffic, and I noticed that the temperature was getting high as time was passing by. At one point I had to stop because the temperature was at its highest point. When I opened the bonnet I could notice white smoke coming out of the radiator. I stopped the car and I let it cool down. When I opened the top of the radiator, a black jelly-like liquid came out of it. I let it cool for some hours and then I refilled the radiator with water, the temperature did not get very high but remained stable. The car worked perfectly well. Can you tell me what happened to my car, please?