Greg from Long Island is pretty sure that his radiator is now holding a mixture of equal parts water, coolant and sealant resulting from his vain attempts to plug up his leaking heater core. Is there any hope for Greg or should he just relocate the cat's litter box to catch the drips? Find out on this episode of the Best of Car Talk.Get access to hundreds of episodes in the Car Talk archive when you sign up for Car Talk+ at plus.npr.org/cartalk Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy