P0128 fan is constantly on when dash says — — —, P0014 sometimes comes on

AONEAL10515

MEMBER
2009 CHEVROLET COBALT
2.0L
4 CYL
2WD
142,931 MILES

Code p0128 is constantly on and p0014 comes on occasionally. It’s about 7 degrees Fahrenheit outside today and my fan near the front bumper is on and thermostat says 95 degrees Fahrenheit. My car has been warming up for twenty five minutes now. I cleared the p0128. The fan stop, heat got hot again, and now the temperature is going up. I replaced the thermostat already with a fail safe one because of this issue and I’m still having this problem. What’s the next step to replace: cooling fan, coolant temperature (ECT) sensor, or intake air temperature (IAT) sensor?
The fan kicks on when the coolant goes - - - on dash. Coolant was replaced with thermostat. Coolant level is exactly where it should be.

For p0014 oil has been replaced but I pretty sure he didn’t replace the oil filter. I know 02 sensor was replaced. Car rpm's drop then it will throw the code. Also, if it acts sluggish for too long it will throw the code. Should I start with oil filter, actuator, or a sensor? Mechanic says to start with cam or crankshaft sensor, but when looking it up it replacing the sensor doesn’t make sense.

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1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon,

The 128 is for low engine temperature. The thermostat is the most common failure for this issue.

https://www.2carpros.com/articles/replace-thermostat

The 14 is for dirty oil in the cam actuator. You need to flush the oil system and try to get all the sludge out of the passages. You can use sea foam from a parts store. Add it to the oil and let it idle for about one hour and then drop the oil and filter. you may need to do this several times to get the sludge out of the system.

Never, ever change your oil without changing the filter.

Clearing codes does nothing until diagnostics are done and repairs performed.

Roy