Hi I have a 2003 C220 CDI that has just developed engine smells inside the car . 1st they wer diesel fumes that the repair garage said were due to a cracked breather tube. since this has been replaced I have now beed getting what appears to be exhaust fumes comming inside the car. This only happens when I switch on the heater or aircon. Any ideas on what is happening as the situation is not good?:???: