So this morning started the car as normal engaged reverse and then this loud hoover like noise started when i gave it some revs, this continued until the engine got warm (12 degrees outside) about half way between the 60 and middle on temp gauge.
Spoke to a guy i work with and he said it may be a secondary air intake that heats up the CAT when its cold to help with emissions?
Does the focus have this? googled it and there is a part but ive not been aware of it before now.
Focus 1.8 TDCI