I have a 2009 C5 1.6 110 which has suddenly developed a power loss fault while driving home. if I leave it a while and start it seems to run fine for a couple of mins, then I get a loss of power, it will accelerate up to speed limits but is very slow and there is a humming type of noise that matches engine revs (noise only there when fault comes on).
The engine will rev freely but will not pull in gears, it pulls ok to about 1700 RPM then very little power after that. Last service by the garage I normally use 6000 miles ago and diesel filter change. I have spoken with garage whos initial thoughts are it could be dpf but car shows no faults on the dash and no faults when I press the service button.
has anyone got any ideas what it could be? so I know what I'm looking at repair cost wise? or possible fix myself