What could cause the coolant system to continue building pressure/ cracking radiator ever after replacing thermostat and water pump?
My car has an automatic transmission.
It may be that you have a head gasket leaking combustion pressure into the cooling system causing pressure to build up there. In order to check for the blown head gaskets, you will first need to have the cooling system pressure tested to see if it holds pressure, and then you will need to have the radiator tested using a special tester that can detect combustion gases there. If this test is positive for combustion gases, then you will need to have the cylinder heads removed to check for bad head gaskets or cracked cylinder heads. If you would like some professional assistance with this diagnosis, consider contacting a certified technician, such as one from YourMechanic, to assess your coolant pressure problem.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing