1996 C250 Diesel Coolant leak problem.
HI guys , there is ( and has been for some while ) a small coolant leak in my 1996 C250 car. I can see the coolant on my driveway after parking there a few hours and have had to top up the Coolant every 2,000 miles or so. Recently I am having to top it up on a much more regular basis and its getting annoying at this stage. I left the car into my Mechanic ( who is very competant ) and he cant see/ find any leak , he even pressusised it .Can anyone give me any ideas on how I could source this leak please. I have a funny feeling it could be something to do with the Air Heater Fan system because during the cold periods when I am using the heater I seem to have to top up the Coolant a bit more . Any help greatly appreciated.