Wrong mixture make sure you have pre diluted/mixed coolant/antifreeze.
Bubbling coolant usually indicates a head gasket problem...
change the coolant fan relay
thermostat is stuck shut
headgasket leak and exhaust gas is getting into the coolant
thermostat or blown head gasket....
1) Your engine is overheating and the coolant is boiling. Or 2) Exhaust is leaking into the coolant, probably through a bad head gasket or cracked head.
Bubbling coolant in your 2000 Ford Expedition could indicate several issues, such as overheating, a blown head gasket, or air trapped in the cooling system. Overheating can cause coolant to boil and create bubbles, while a blown head gasket may allow combustion gases to enter the cooling system, leading to bubbling. Additionally, insufficient coolant levels or a malfunctioning thermostat can contribute to this problem. It's important to diagnose the issue promptly to prevent further engine damage.
Coolant bubbling in the expansion tank typically indicates the presence of air or gas in the cooling system, often caused by a blown head gasket, a cracked engine block, or a damaged cylinder head. This can allow combustion gases to enter the cooling system, leading to pressure fluctuations and bubbling. Additionally, overheating or low coolant levels can exacerbate this issue. It's essential to diagnose and address the underlying problem to prevent engine damage.
The coolant level is low in the truck.
/the water circulating noise could be low coolant in the system. If the coolant is bubbling in the overflow bottle, then check for a blown head gasket causing the noise.
It is probable that you have a blown cylinder head gasket. It's possible you need a new thermostat. Depends on where it is bubbling from. From the top of the engine? Cylinder head gasket. From the overflow on the coolant reservoir, thermostat.
You have a cracked head or a bad head gasket. Don't drive it, you make cause more damage doing so.