Had the thermostat changed back in October, didnt work to well, took ages to get to operating temp. Never overheated though. Called volvo and they just swapped in yet a new thermostat, much the same issue now. Waterpump is ok.
I was there when they changed the thermostat the second time, noticed they did nothing to air the system, just filled reservoir and sent me on my way.
Is there not a procedure for venting air in the system?