Code P0128 - replaced thermostat

[DodgeaWrench]

[2014 DJ 3.6 177k miles]

 

Solid yellow check engine light came on.  Code P0128 - Coolant Temperature Below Thermostat Regulating Temperature.

 

This occurred once before, approximately 5 years ago, so I had a clue as to what was happening.

While taking a "test" drive, I toggled through the display to show coolant temperature.  Coolant temperature would not rise above mid-180 Fahrenheit.  (My understanding is that it normal should be above 200-ish).  Time for another thermostat.

 

As repairs go, replacing the thermostat is one of the easier repairs to do (2 10mm bolts and a spring clamp, easy access).  Having a spring clamp tool (on a cable type) makes it a breeze.

 

As mentioned, mine was replaced once before at 109K miles Jan-2020 $260.00 (repair shop, not dealer).  A Mahle brand thermostat was installed.  I went to a repair shop instead of doing it myself as it was the middle of winter and I do repairs in the driveway.  This time it is a beautiful fall weekend to take advantage of, with winter soon to knock on the door.  No time to order an OEM.  I went to the local auto parts store and purchased a Murray brand thermostat $19.00.

 

After the swap, the code was reset and a small test drive afterwards had the temps rising into the low 200's with the check engine light stayed off.

Next is to watch for leaks.  I'll post a follow-up in about a week.

 

 

 

   

 

 

The old thermostat in location

 

 

 

The new

[yyz]

Worst part I find is that stupid plastic bleeder screw.I replaced mine with a brass one.

[larryl]

I just reset mine I like it running cool....

[14WhiteRTRallye]

Mopar stat is a Mahle in a Mopar box. I found out the expensive way.

[Daniel Anderson]

Larryl what oil temperature are you getting

[larryl]

usually around the same as the coolant temp rarely over 205* 

I use 5-30 oil also approaching 210000 miles no consumption so far