A Hello in the group I have a Peugeot 3008 HDi 1,6l 2012. To the problem. Temperature indicator fluctuates slightly here and there. Car cools down quickly, especially when driving slowly and service life. Everything else is still working perfectly. Keeps up to 90 degrees there with just these slight fluctuations. Heating works fine. Thermostat, water pump, cooler lid has been replaced. Several times professionally pushed off by the mechanic and ventilated. At Peugeot asked and no solution until now. Cooler remains almost completely cold from the front right, as well as the lower hose, which remains ice cold. No water loss available. No blubbering in the compensation tank. Now the question still has an idea where the pressure loss could come from? The question independent of the car, which cooler part, engine part can otherwise make sure that pressure in the cooling system is lost without water loss?