Why does the lower radiator hose on a Subaru 2.2 l engine stay cool?

The lower radiator hose on a Subaru 2.2 L engine should not remain cool during normal operation. If it does, it may indicate an issue with the engine's cooling system. Here are a few reasons why the lower radiator hose might stay cool:

. Thermostat problem: the thermostat regulates the flow of coolant between the engine and the radiator. If the thermostat is faulty or stuck open, it may prevent coolant from circulating properly and reaching the lower radiator hose. This can cause the hose to remain cool.

. Blocked radiator: A blocked radiator can restrict the flow of coolant and prevent it from reaching the lower radiator hose. Blockages can occur due to accumulated debris, dirt, or corrosion within the radiator.

. Faulty water pump: The water pump circulates coolant throughout the engine. If the water pump fails or its impeller becomes damaged, it can reduce the coolant flow and cause the lower radiator hose to stay cool.

. Air pockets: Air pockets in the cooling system can prevent the proper circulation of coolant and lead to a cool lower radiator hose. Air pockets can occur during coolant changes or when the system is not properly bled.