hey people. i have a 2005 E46 320CD and i have noticed a problem with the temperature gauge. When i am driving around town the needle stays at the halfway point. When i then go on the motorway i notice that the needle drops close to the blue mark on the gauge. I had the waterpump replaced last year along with the thermostat. I also bleed the coolant system to see if it would solve the problem but didnt. Any help would be much appreciated.