I have a '11 S, that I got last year with ~25k on it (one owner, full service records from dealer). I've since put about 10k more on it and aside from a couple half-engine lights lasting just until a restart of the engine, it's ran great.

About a month ago, I lost my key, and it took until last week for me to finally be able to get the $200 replacement. In that time, my MINI was parked in the driveway from when I last drove it home.

I made a short drive down my road, and immediately noticed a faint buzz/whine from the engine. It sounds like it's coming from the passenger side (later listened with the hood open, revving it in driveway, and I can't pinpoint it to anything, but it still sounds like that side of the engine)


The dealer is an hour away, and I'm out of warranty time frame, so I'd like to do as much as I can to figure this out on my own.

What could have happened just sitting for a month? And what should I be checking?

Thanks

 

Just an update:

I took it for a longer drive yesterday and found a couple things I hadn't noticed in my shorter drives:

First being that it only happens up until 4th gear. I have an automatic, but in selective shift mode, even up to 3500 in 5th gear I can't hear the sound. 2500 and up in 1st through 4th, and it's there.

It doesn't just stop when I let off the pedal. I swear it was the first time, but I'm certain that now it's as long as the engine is above 2500 it will make the sound relative to the rpm.

That being the third thing, it's an electrical whine(?) and will vary in pitch with the RPM. I don't know all the terms of sound, so it could very well just be getting louder and sound different because of that.. but either way, it's louder/higher pitch whatever at say 3500 than it is at 2500

So if I'm crusing at 55mph, and I take my foot off the pedal, it will lower pitch as it decelerates to 2500rpm, then when it downshifts (if I'm in regular D) and it gets that pickup in RPM, it will go back up in volume/pitch, then repeat for each downshift.