I'd read that the 3.2 is a strong reliable engine myself but I know nothing's bulletproof (mechanically speaking). I'm getting it checked into a nearby Audi specialist soon and I've written down what you said so that they can check it. Taking it in as I don't trust myself to do it personally.
Best get it checked in case it turns into a bigger problem in the future.
Thanks to you all for helping, anything goes missing in your house and the worlds greatest detective is right here !