The noise only occurs when in gear and accelerating...
I'm not a mechanic and don't really know much about the ins of a car... but I've read a bit, looked online, and am excellent at guessing 🙂
When idling, i.e. not moving, but engine running; it sounds fine, almost perfect.
When moving, if i take it out of gear, it sounds fine. there's no drag, or any evidence of drag.
As soon as I put it into gear and accelerate, the noise happens... it's a kind of grinding/squeaking noise.
My guess is purely by process of elimination... I don't think it can be the engine as only happens when in gear. So it may point towards the gearbox? or bearings somewhere down there?
The "Check Engine" warning light has been on for a few days as well as the "vehicle dynamic control" one... this first appeared a month ago, but turned off after putting in some diesel injector cleaner. Didn't work this time. They both came on together, turned off together and then back on again.
No idea if the two issues are linked. Hopefully they are!
The car is booked in to a garage tomorrow (Tuesday), so I guess I'll soon find out what the problem is. I just hope it's nothing too expensive!