How Does Oil-Immersed Vehicle Pressure/Temperature Sensor Detect Fluid Temp Through Insulation?

Hello,
I have a pressure/temperature sensor for a vehicle, which I decided to tear apart to see exactly how the sensor works.

This sensor as designed by the manufacturer is meant to be immersed in oil to detect fluid temperature and sense gauge pressure. The pressure sensor side of it seems pretty straight forward in that there is a hole in the sensor physical body and PCB.

I am stuck on how the temperature sensor works in this specific sensor, if you look at the picture I attached the entire PCB is covered in a glue like substance I am guessing to insulate it from the oil. The temperature sensor is covered in the glue like substance aswell as some sort of cement like substance and is bonded only to a metal rod.

I am a little loss as to how the temperature sensor would be able to detect change in the fluid temperature if there is all the insulation glue on the board isolating the sensor from any fluid. My only guess is the metal rod acts to conduct heat towards the temperature sensor on the PCB. So to prove this I have tried measuring the temperature signal via a pin on the sensor and a oscilloscope. I've immersed the sensor in oil, raised the heat of the oil and applied the proper 5 V to the sensor. For some reason the temperature signal will stay only at 1.3 V regardless of oil temperature.

I am beginning to think maybe the sensor can only read the temperature with a pressurized fluid, and not just sitting in fluid. Any input is appreciated thanks

Does the sensor gives an I2C or one wire output in which case altering the temperature just changes the serial data and the average voltage is much the same. But presumably your scope will detect this.
Covering a sensor in glue does not necessarily make it inaccurate but just slower to respond to changes. But that does assume that the rear face of it is also at the same temperature. If the rear side is conducting heat away it will be inaccurate.

Sorry forgot to add that its a analog thermistor,no serial interface i could try soaking the sensor in oil again i did however have the sensor submerged in hot oil for around 5 minutes with no change in the temperature signal.Here is another picture of what the sensor looks like when fully assembled.Iam just baffled as to why i cant get the temperature signal to change voltage

The only other reason i could think of that is causing no voltage change to show up when the oil is heated, is i need external circuitry somewhere.But looking at the pcb it seems that they have the thermistor in series in a voltage divider network i should just be able to probe the signal wire and not have issue's.

Ok so a update i heated the oil again to 100F and submerged the sensor in it again but waited longer then the 5 minutes.I used a DMM this time and the temperature signal was reading around 0.785v and would increase 0.001v for every 5F in increase of oil temperature.Now iam thinking it would need a opamp on my end to make the circuit a 0-5vdc analog signal?

As for getting data from the sensors, there must be some time required so that the sensor starts providing signals. Similarly when we use the thermistor or other temperature sensors, there is some time required for the sensor to get the readings after that it provides signals and also when there is a small change happening in temperature then the signal value will not change at the same time. For better checking, we need to attach some external circuitry with the sensor. It is better to use a micro-controller analog pin, to get readings from sensor.

As for getting data from the
sensors, there must be some time required so that the sensor starts providing
signals. Similarly when we use the thermistor or other temperature sensors,
there is some time required for the sensor to get the readings after that it
provides signals and also when there is a small change happening in temperature
then the signal value will not change at the same time. For better checking, we
need to attach some external circuitry with the sensor. It is better to use a
micro-controller analog pin, to get readings from the sensor.