Loss of oil and low temperature gauge reading.

[Jollyno]

Greetings everyone, I am new to the world of Mercedes and my experience so far has been less than satisfactory. Multiple problems have been identified with a 2011 E350 CDi, but the most recent one is a noticeable smell of burning oil. An independent expert has determined that the cause of this issue is related to problems with the oil cooler and the main rear seal. All substitutions have been made.
I am now experiencing an issue where the temperature gauge remains stationary or only reaches a maximum of around 60 degrees.
When the gauge is stationary, the ECO light does not illuminate, and the function is not functioning.
Do you have any suggestions or thoughts? Temperature sensor?

[Finestey]

Possible causes for this issue include a malfunctioning thermostat or the presence of an air bubble in the cooling system, which hinders the transfer of heat to the sensor.

[Jollyno]

Is it prone to easy bleeding?

[Cincoon]

Simply remove the filler cap, start the car's ignition, and allow it to reach the desired operating temperature.
If there is still air in the system, you will see air bubbles at the top of the radiator.

The Eco light will only illuminate after the vehicle reaches its optimal operating temperature, which typically ranges from 85 to 90 degrees Celsius as indicated by the new thermostats.
If attempting to purge air from the cooling system does not result in an increase in the coolant temperature, it is advisable to consider the possibility of requiring a replacement thermostat.

[Jollyno]

Based on my analysis, it is most likely that the issue is with the coolant sensor. This conclusion is drawn from the observation that the temperature dropped abruptly from 60 degrees to 0 while driving. Restarting the automobile restored the temperature to 80 degrees.

[Cincoon]

Highly probable. That detail was omitted from your original message.

[Jollyno]

It has recently been completed.
Is the thermostat assembly and sensor considered as a single unit?

[Cincoon]

The coolant temperature sensor and the coolant thermostat are distinct components.

Section 85 in the first diagram
Refer to the second diagram and locate Part 20.

https://nemigaparts.com/cat_spares/epc/mercedes/1/m/642852/d51/15/105/?chasis=212023D01

https://nemigaparts.com/cat_spares/epc/mercedes/1/m/642852/d51/20/015/?chasis=212023D01

 

[Inspirli]

Regarding the OM642 engine, I cannot provide a definitive answer. However, as a general observation, it is common to find two distinct sensors. One sensor is responsible for measuring the coolant temperature and transmitting this information to the Engine Control Unit (ECU). The second sensor, known as the coolant temperature sender, is responsible for providing data to the temperature gauge shown on the dashboard. It is advisable to investigate more.

[Bridgenix]

I have recently seen that my vehicle, namely an om642, is exhibiting unusual behaviour. Typically, it takes a significant amount of time to reach a speed of 80. The only effective method seems to be increasing the engine's revolutions per minute. However, today the temperature reached around 70 degrees and thereafter dropped to 0 for the remainder of the trip. After a restart it began operating again, however given the figures it shows am not convinced it is particularly accurate. Would an OBD scanner provide any real-time data for comparison?