On the way home from a 60,000 km service, I noticed there was an unusual sound coming from behind the dash/centre console.
It's more noticeable when accelerating from stationary and just when I start the engine. It sounds like air being sucked into a tube.
Could this be air in the cooling system? Since the coolant flows behind the heater (for heating), could this be the flow of bubbles/air pockets behind the console that I am hearing?