Over heating

mabynack wrote:
A good radiator shop can give you a better diagnosis. They can put a pressure gauge on the radiator to see if you have a leak or if the head gasket is leaking. They'll also check the radiator cap to make sure it's holding the correct pressure.

Sometimes the radiator cores get clogged and back flushing isn't enough to remove the gunk. You might need to get the radiator re-cored or replaced. An easy way to check it is to get one of the 15 dollar IR temperature guns and check the temperature of different parts of the radiator. If there are cool spots on the radiator it indicates that it's clogged.

This is a must have tool with a hot running 454. To add some detail to maybacks post. Get the eng up to operating temps then shoot the inlet on the top of the radiator and take a reading every 4 ins from top to bottom in a grid pattern. Radiators usually block in the center so if you see colder temps in a circular pattern you know you have blockage. On mine I had a deta T of 50 degrees from top to bottom. I thing you need to see at least 30 degrees difference to have a functioning radiator. In addition you can shoot the sensor in the LH head and compare that reading to your thermostat housing temp then look at you dash gauge they should be close, the temp sensor and gauge should be the same and your housing a little less. After you climb a hill does the temp recover quickly as you go down? Does it overheat at idle on a hot day? There are a lot of things you can do to cool a hot running 454 but start with the basic things first, then post back with your answers.