Heaters. Will take longer because of cold wether. But You may need a heater resistor If thats fine then id look into thermostat. As for engine noise. If when you depress clutch and come off accelerator you will possibly need a release bearing. If Its just the Accelerator your pressing (Clutch is left alone) A:Possibly a Cam-belt (i think should be changed every 100,000 miles) B:Polly V belt more then likely your belt tensioner will require changing.
Ex Citroen Tech, February 2009