2001 Chevy Cavalier Coupe. 2.2 4cyl.
Check Engine Light codes  P0128.
Repair done prior = A year ago hired a mechanic to supposedly change thermostat due to overheating engine. Done to repair = Went to Autozone and got the code P0128. Sales associate suggested i change the thermostat so i purchased one and   "replaced" it today. Also just found out today that the mechanic hired last year to replace old thermostat never put in a new one. No wonder during the winter months i had no heat...
Question = My check engine light came on about 1 week ago. I brought it to AutoZone and they gave me a Code P0128. Probable causes: Check Coolant Level - checked and ok Thermostat Defective - put a new one in today ECT Sensor Defective - No replacement part available at AutoZone.

After placing the new thermostat in place and filling the reservoir with fresh antifreeze (50/50 Dexcool), I turned on the ignition and then noticed the engine temperature gauge raised up too fast just past the halfway point in a matter of minutes. Check engine light still on.

It is possible the sensor is bad, or you have air in the cooling system. This  code normally comes on because the engine coolant temp has not reached normal operating temp within a per-determined time. Air pockets around the sensor will cause it to not read properly. Suggest replacing the sensor and bleeding the system.
2001 Chevy Impala coolant fan keeps running after the engine is off. The temperature gauge quit working at the same time. Any suggestions? Thanks,Candy

if you are referring to the radiator fan, it sounds like you are describing a pretty common problem. I'll bet the check engine light is on also. If it is then you probably have a trouble codes stored – P0128. This code is described as "coolant temperature below thermostat threshold". Basically the thermostat is stuck open and the engine is not getting to operating temperature. That's why the gauge looks like it quit working but is just showing cold coolant temperature. The fan staying on is the computer going into sort of a safe mode. Since it does not know what temperature the coolant is, it turns the fan on in case it's too hot, to prevent the engine from overheating. Get the thermostat replaced, the code cleared, and you will be good to go. This is assuming that your antifreeze is not low. If it were low you have the same problems as above. So check that first.
2001 Chevy Cavalier P0128

More Car Repair Help