The head gasket blew.
It appears that your Dodge Magnum has a blown head gasket. In most cases, when a head gasket blows, it is due to the engine overheating or contamination of coolant. The coolant mixture should be 50% coolant and 50% distilled water. Use of only distilled water as this will keep out minerals in tap water that calcify and rust along with avoiding of build up in the cooling system. This can reduce the efficiency of how the engine is cooled.
Build up of debris can rub against the head gasket and create a weak point at which it eventually fails. In most cases, if the engine is in good working order, the cylinder heads can be removed and sent off to a machine shop to be cleaned and resurfaced so a new head gasket can be installed.
I would recommend enlisting the assistance of a certified mechanic, such as one from YourMechanic, to come by and have a look at your Dodge Magnum. They will be able to confirm that your head gaskets are indeed blown and evaluate the engine and entire car to determine if your Magnum is a good candidate to perform the extensive service of replacing the head gaskets.
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