Hi folks.
I have not yet had a chance to properly inspect but all the symptoms point to such a leak. All but disappears after then engine has been warmed about 15-20 mins which I would explain as heat expansion closing the leak. Vehicle makes the same sound in park, neutral, driving straight or turning right.
What puzzles me though is that if I do left turns or drive left in circles the sound cuts out. This is the only thing that makes me question this diagnosis.
Is it even conceivable that when turning left there is for some reason strain/torque on the engine/manifold/exhaust that is pinching the leak shut temporarily?
2009 Volvo XC70
Thanks!