Question

1. a technician removes and replaces a worn lower radiator hose on a four cylinder engine. the engine overheats after replacing the hose and adding coolant. which of these is the most likely cause of this condition?

a faulty ect sensor.
a stuck open thermostat.
an air pocket in the system.
electrolysis.

Explanation:

Step1: Analyze ECT sensor

A faulty ECT (engine - coolant temperature) sensor may cause inaccurate temperature readings, but not necessarily immediate overheating right after hose replacement and coolant addition.

Step2: Analyze thermostat

A stuck - open thermostat would allow coolant to flow freely and would not cause overheating. It is more likely to cause the engine to take longer to reach operating temperature.

Step3: Analyze air pocket

When a radiator hose is replaced and coolant is added, air pockets can form in the cooling system. These air pockets can block the flow of coolant, leading to engine overheating, which is very likely in this case.

Step4: Analyze electrolysis

Electrolysis is a chemical process that can damage the cooling system components over time, but it is not a common cause of immediate overheating after hose replacement and coolant addition.

Answer:

C. An air pocket in the system.