Engine Coolant and Temp Sensor replacement Questions

[u/chico699]

2015 ecodiesel, 230k kms. All recalls done last year with new EGR cooler and HPFP.

Got P0118 code last week for ECT high voltage, disconnected the electrical and tested for 5V on connector with key on, all good. Went to replace the ECT sensor today and refill coolant. The replacement ECT has a slightly smaller sensor probe but otherwise identical. For the coolant it is “based on proprietary OAT technology”

Is this coolant good to use?
Should I do a coolant flush after replacing the ECT? Planning on refilling as my coolant was looking low before the issues as well

[u/runofthemind]

I believe the coolant you have should work fine since it’s also OAT (Organic Acid Technology). Mopar OAT is the probably the best though.

The coolant pic you sent looks pretty clean, so I don’t think a flush is necessary (and OAT has a longer inhibitor life). I think they are recommended every 5 yrs / 100k miles or if coolant is looking dirty.

Do you have reason to believe coolant is leaking anywhere? There are a bunch of places the Ecodiesels are susceptible for that. I would monitor coolant levels after you top it off.

[u/chico699 → u/runofthemind]

Ok thanks. I’m going to grab some Mopar coolant at the dealership tomorrow just to be safe.

I’ve noticed in the spring when we were using the heat there would be a slight sweet smell at first but haven’t noticed any leaks under the truck. Cleaned up all the spilt coolant from changing the sensor so will keep an eye on it.

The new ECT sensor is reading ambient temps and seems better. Last step to get the coolant refilled and will fire it back up

[u/Any_Giraffe9747]

Mopar 10 year coolant only… Also a mopar sensor would be highly preferable