Fiesta Low Growling Noice At Low Revs

Hello

Over the last week or so I've noticed a low growling noise coming from the front passenger side when the car reaches 1500-2000rpm (closer to 2000rpm) and makes a low growling noise for about half a second.

This happens across all of the gears when driving casually (as my driving habits are quite economical) and isn't really specific to a cold start on a morning or when at optimal running temperature.

This mainly happens when building up speed but can also be replicated by going uphill to start labouring the engine and not changing down to a lower gear it is much easier to replicate this condition.

Cash flow is a little tight at the moment with cutbacks in my hours at work so I can't book my car into the garage straight away, but if it's a must, I just want to come across, that I know what I'm talking about, so I don't get ripped off left, right and centre.

I know it's hard to describe a noise without being able to let you hear it but if you could give me some scope to start investigating, I'd greatly appreciate it.

Thank you in advance :)

Edit: *Discontinuing discussion in this thread as I've since had some developments and need to discuss in a more relevant thread* Thank you.