Whirring sound coming from engine bay. Diagnostic help please. 1.9 tdi ASV 110 (vp110)
Whenever the car runs, there is a constant whirring noise. Its 92k mileage and had a cambelt done in 2019 (30k miles since). The car runs completely fine.
Update: I checked and ive done 430 miles since i bought this car 23rd april last month. I listened closer and I originally thought it was the CCV, the noise seems to be from the timing section, im thinking the very top, specifically the timing belt deflection pulley. The noise was more pronounced when i take the belt cover off, but the belt looks clean and healthy. This noise has been around since i first got the car (it happens when the car is warmed up) i checked a video of the same noise and source and it was 26th april after a spirited drive.
It could also be a vacuum leak.
Any help is greatly appreciated.