hi, I’ve been having problems with the cooling water and a stuttering motor in the empty run for 2 days now. cool water now drained 2 times and filled up. ventilated in which I left the cover of the balance tank open, motor running and heating on full pulley. so far so well. drive now and the motor gets hot comes the red coolant lamp and it’s actually missing coolant. let the motor cool down is the stand again perfect. but the biggest problem is that the motor has been in for 3 days empty run stutters when it is warm. I stop and turn the cover of the filling tank carefully on warm motor, escapes air. then also the stutter stops. throttle flap I had overtaken 4-5 months ago by ecu. also has nothing to do with it, as I said the stuttering goes away when I leave air out of the cooling system as described above by turning the lid on hot motor. volvo v701 2,4 ez 1999 thank you for help.