I am trying to diagnose what could be a failing pulley, before just throwing parts at the Mini.

Last week I experienced almost a complete loss in power, while driving and what felt like a misfire; the Mini threw a P1688 code. I cleared the codes, left the car to rest for a bit, then fired it back up and limped it home. The drive home was fine, though the supercharger seemed to "wind down" whenever any acceleration was given to it - Winding down sound - There was the smell of hot rubber as well. After some research, everything seemed indicative of a failing/failed crank pulley. Though upon inspection of the pulley, there doesn't seem to be any evident separation between the two pieces - Crank pulley image - Though it has developed a little bit of a squeal upon throttle being applied. I captured a video of the crank spinning that includes the squealing sound. Please excuse the oily mess. Tracking down all the leaks are on my projects todo list. Lol

I am a bit over my head here in diagnosing the issue; the R53 has been a learning project for me and has come a long way from where it started. I am hoping there may be some help that can be given to point me in the right direction?

Thanks!

 

Have you seen this?: https://www.dtcdecode.com/MINI/P1688

 

Thank you.

I have not seen this page exactly, no. But my scanner gave me the brief, and I will have to dig into that as well.

But it seems like that might be separate from the supercharger spinning down and the squealing?

 

Yes, separate the noise from the code. When you go into limp mode and clear the code but not cure the cause, anything over about 3000 rpm will put it back into limp mode.

 

Classic crank pulley symptoms. Especially the burnt rubber smell. Mine didn't physically separate until I pulled it off but it did split neatly into to two halves like an English muffin.

Outside chance it could be another pulley failure; idler, alternator, AC, supercharger. Would think those would show up with bearing noise though and a lot more belt squealing. Would pull the belt and right side wheel liner and spin each pulley to get a better idea. That said, with anything over 100K miles - mine went at 50K - would ditch the factory pulley anyway and get an ATI or SFI/PRW. It's a known weak point and day ruiner.

That's most of us here. You've come to the right place, and welcome.