Hello all.I have just installed a new rad in my 91 N/A 1.6L golf. This is the first time I have worked with a sealed system like this and found getting the air out of the system way harder than removing and installing the rad. After newmerous burps I got the temp guage to settle into it's middle position. The problem happens when I "occassionally" :wink: take the car in excess of 120kph. When I do this the temp falls to cold and I have less heat. My father said I probably had a air blockage in the heater core. I took the hoses off with it running and not running and did a one hour test run and it's still happeneing. Suggestions are greatly appreciated at this point. Thanks in advance.Greg