Hello,
That is a good thing that the pace did not change when you increased the revs. Most likely what you hear ticking is the purge valve. This runs to clear the hydrocarbons (unburned fuel) that is in the charcoal canister. This function will run when cetain criteria is met. It is common for customer to ask about this ticking noise. Sometimes you will hear it and sometimes it will not be running but it has a distinct ticking noise that can be heard with the hood down. As long as no check engine light has come on this was most likely the purge valve functioning normally.
I hope this helps. Thank you.
BMW Mechanic
Level 1 BMW Master Certification, 9 Years Dealer experience, Team Leader, Shop Foreman