P0128 Chevrolet -

Question

so when does a person change the thermotat how often does it need to be changed

Answer 1

P0128 Engine coolant temperature below thermostat regulating temperature

When the coolant is serviced the thermostat should also be replaced. The coolant is serviced at if you are using the recommended coolant which is DEX COOL you service at 5 yrs / 150,000 miles, if you are using conventional coolant which is conventional green it is serviced at 2 yrs/ 30,000 miles. The thermostat should also be replaced if there is ever a overheating problem, When the engine ever overheats the thermostat changes it characteristic and will no longer function as intended. you replace it then also. Your code condition you have is P0128 which means the thermostat is open sooner than expected,

Here is a thermostat that set a P0128, this thermostat is stuck in its open position. being in the open position prevents the engine mangament to maintain fuel control. and use more fuel than intended.