A: There are a few very good products available that are labeled as “head gasket sealer.” My favorite is the Blue Devil brand, which is available at automotive parts stores. ... The sodium silicate costs around half the price of the automotive products.

Why is my car overheating after I put blue devil in?

You might have clogged heater core. The whole system has to clean otherwise you will have overheat in stop n go + no heat when you need it.

Is Blue Devil bad?

Is Blue Devil Bad for Your Engine? The answer is a resounding no. And if you are wondering about the safety of using other brands of rear main seal conditioners and stop-leak products like Bar's Leak or Justice Brothers, don't worry. They almost all use the same active ingredient.