2003 3.8L Questions

[MurphysLaw88GT]

My g/f has a '03 Buick Regal LS and it is the N/A 3.8L (L36?). She briefly threw a DTC for a few days. It is P0128 it was something about coolant temp below threshold or something to that effect... This leads me to think her T-Stat was sticking or she may have a faulty coolant temp sensor as obvious things to check. What would you think, any other suggestions?

The MIL light would come on every once and a great while. It is now off and has not been on in a few days. I ran codes and it was still in the memory, if anyone has any suggestions or if this is a common thing on these things let me know. Thanks for your time.

[BAD LS1]

If the coolant is below 165 sustained to get 2 errors out of it it will flip the SES light on. So yes either the sensor is failing or the T-stat is stuck open etc... I had to turn this code off on my S10 when i hada 160 T stat in it.

[MurphysLaw88GT]

Thank you Tom.

[brotherbenn83]

Those coolant temp sensors fail ALMOST NEVER. If you want, put a t.stat in it, they cost about $15 and take about 2 minutes to replace on a 3.8L. EVERY car I have ever had with a P0128 "engine coolant temperature below thermostat regulating temperature" was fixed with a new thermostat.

[BadAzzGTA89]

Mine does that in my Regal GS form time to time when i "get on it" in the cold weather and i replaced the coolant temp sensor and it still did it i just reset the light no big deal!