CEL on and off, OK to drive for a while?

[jdeare]

2001 Buick Regal LS

CEL has come on 4-5 times in the last 2 weeks, but it then goes off after another ~50 miles. Code is P0128, coolant/thermostat/coolant temp sensor.

Coolant is fine, so I figure I will start with the thermostat, but it's really cold right now. Is it OK for me to drive it like this for a while, say 2-3 months? If I have to I will have a mechanic do it, but it's a pretty easy fix... but without a garage it will be a nightmare in this weather...

 

[Herz]

If your car is not running up to temp, then you may get extra fuel in the oil, less MPG, not really ideal to run like that. When your motor is not at the correct temp the computer tells the fuel system to dump more fuel to warm it up.

 

[daman]

This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostat.

In determining the engine did not reach a "normal" temperature, it takes into account the length of time the vehicle has been running, the intake air temperature (IAT) sensor reading, the engine coolant temperature (ECT) sensor reading, and the speed of the vehicle.


You will likely not notice any drivability problems other than the MIL illumination.
Causes

A code P0128 may mean that one or more of the following conditions has happened:

Low engine coolant level
Leaking or stuck open thermostat
Faulty cooling fan (running too much)
Faulty coolant temperature (ECT) sensor
Faulty intake air temperature (IAT) sensor
Possible Solutions

usually it's a thermo..stick with OEM GM stats..

 

[fdcg27]

Do you have heat while driving?
If so, the coolant is at least reaching a reasonanble temp.
If the thing appears to be reaching normal operating temperature as you drive it, I think that the themostat should be okay until warmer weather arrives, and you can change it without dying of exposure.
If the car seems otherwise okay, continue using it, and see what happens.
If the thermostat is really stuck open, you won't see any heat at all on a cold winter day.

 

[jdeare]

I have not noticed anything except the light so far, I know it's not ideal...

I have some heat, but that's the way this car has always been. According to the temp gauge it's getting to 1 notch below pointing straight up (I do not know what temp this corresponds to).

I will wait and see what happens. If I lose heat completely I'll take it in I guess.

 

[Slippery_Pete]

Check the wire to the sensor. It is located under the tstat next to the exhaust pipe that is there. There is a small clip that retains the wire and if it breaks it would burn the wire to the coolant sensor.

 

[jdeare]

Thanks! I will check that wire ASAP.

 

[Eddie]

Some engine parameters will trip a code if it misses the "good" operating window 5 times in succession but, will go off if it doesn't repeat for the next 10 cycles. I would guess that eventually it will fail permanently and the light will stay on.

 

[snowmaker]

Funny, some cars keep the CEL in it for up to 45 starts..If it is in there some many times some states will not pass inspection...I think you will be replacing an item soon.