Joined way back in February, but just now getting to this. New member, new to minis, but I've learned a bunch in my short time. Purchased a 2009 convertible S for my son earlier this year. She was cosmetically very nice, but mechanically.....a very neglected old girl. Since then, I've pulled the vanos solenoid & check valve and cleaned(full of oil coking), dropped the oil pan, replaced gasket and dumped plastic debris from previous timing chain failure, replaced front crank seal and drive belt, reset timing, installed a GFB BOV (oem unit was ripped), changed plugs and coils,walnut blasted the valves, replaced air filter....and finally replaced all the vacuum lines. When we purchased, it ran but was noisy and throwing codes all over the place..... but was the ONLY car my son was excited about.. Finally after one last tear-down to check and clean the throttle body(poor, erratic idle at times and complete failure to accelerate when poor idle was present), I noticed that one vacuum line from the vacuum reservoir was not installed. Upon further inspection, I realized that it was hard and no longer stayed in place if you bumped it(90 K miles and 10 years old). I put everything back together and finally. No more lag, rough idle, and unpredictable throttle response. She is now a treat to drive and ready for my 16 year old son!

Lessons learned related to repairing a used mini cooper:
1. Always replace plugs and wires when buying a used car with high miles
2. Replace all of the vacuum lines as they are cheap and readily available.Take the time to study the vacuum diagrams on high mileage, older cars...especially with turbo. I had no idea that there was a series switch for the vacuum line and that there was a reservoir near the back/bottom of the car.
3. purchase some sort of diagnostic tool immediately, preferably before purchasing the car. Bluedriver was awesome for trouble shooting most of the issues.
4. Drive a mini known to be in good order. Then you have a solid reference point for how yours should drive.
5. Enjoy the satisfaction of diagnosing and repairing a car that someone else would have given up on!