03 r53s started squealing last week a little then today it started doing it bad . Then heard a rattle I think I got it home just in time cause it started bogging a little twice for a second. Can a idler bearing make a squeal and I rattle sound? Any help please I need to get my mini healthy it's my only car.

 

Any of the pulley bearings on the serpentine belt side of the engine can scream bloody murder when properly failing.

Take the belt off and feel each by hand. If the tensioner and idler feel fine, check to see if the alternator is seized.

 

I don't think it's the alternator because it still runs and turns I sprayed a little within grease on the pulley under the supercharger and it kinda went away any help I would appreciate it. Thanks

 

check the crank pulley as they are the most common failure causing belt issues. If it is wobbling or you smell burning rubber it is junk and time to upgrade to the ATI damper.
https://www.waymotorworks.com/super-...ulley-r53.html

 

>Squealing
>Rattle
>Bogging

As stated above check crankshaft pulley / dampener, mine went at 55K with 'normal' (no track) use. Reek of burning rubber and P1688 code thrown too. Thought I had a seized A/C compressor, hence the smell of a possible accessory belt melting while trying to turn it but it was actually the vulcanized rubber inside the dampener separating at failure. Bogging could be the car defaulting to limp home mode.
If you hear a rattle, could also be a timing chain / tensioner / guides issue, apparently very common on these Gen 1 cars. Search on "death rattle" and you'll find plenty on this subject to worry about.