Peugeot 207 1.6VTI 5FS thermostat - Low engine temperature thermostat

Hello everyone,

I have a problem with the peugeot 207 1.6vti 5fs 120km 150,000 mileage.
In sequence:
Problem: The engine temperature rises and decreases after driving about 20 km, it reaches the value of 90C and it stays like that at higher revs sometimes it drops. Burning unchanged.

Replaced phase thermostat with sensor.
Now:
Engine does not heat up engine temperature is still 60 degrees. Burning unchanged.

The temperature read by the diagnostic device fluctuates between 58-65C. Phase thermostat control 0% pump actuator is still on (pump is running).

Everything points to the still open thermostat. (Of course the whole system is vented etc.) But would really 2 be defective? The cost of the next one is again PLN 420

Has anyone ever encountered such a problem?

How warm the cooler is, the thermostat lets go.

That's it and I know the question, but why?
Two broken thermostats that behave the same?
It is a phase thermostat, it can have problems with its control only what and on what basis it controls it

I am curious if the problem has been solved. I have a similar problem in the mini, the engine after renovation with a new thermostat (probably phase) does not keep the temperature, on average 70 degrees.

Hello, I'm wondering if anyone can answer, did you manage to solve the problem?

The small fluid circuit, most commonly in the heater, may be clogged. In this case, the pressure of the coolant produced by the water pump overcomes the resistance of the spring in the thermostat and forces the coolant into the large circuit.

What exact engine code?