Hi, i recently had the air con and engine radiators replaced (insurance company provided garage) after hitting a deer on my way home from work in september. After a service in mid november i now notice the water temp gauge fluctuating between just over 60 and just under 80. my journey to work is 22 miles, takes about an hour and involves local roads for a mile till dual carriageway for 2 miles then motorway for 5 miles, then a & b roads the rest. the car usually reaches temp by the time i'm midway up the motorway and stays constantly at ~80. Now the temp goes upto ~80 by the time i'm midway on the Mway and then plummets to ~60 whilst driving and slowly creeps up towards 80 if i'm sat in traffic not moving. If i have the heater on max the temp plummets again. if i pop the bonnet after my commute, the engine cover and water bottle are not too hot to hold my hand against. is this an indication that the water pump is having issues following poor radiator replacement?