Genrational Overview
BMW began producing modern Minis in 2001 with the first generation. All models were hatchback, and trim levels were Base, S, and John Cooper Works (JCW). A 1.4 liter Tritech engine powered the base model. 1.6-liter supercharged powerplants powered the S and JCW. We've been seeing fewer and fewer of these cars, likely because they were not well maintained. The Supercharger was the major maintenance item on the first-generation S and JCW models. The superchargers have two oil reservoirs to lubricate the bearings inside, and that oil needs to be changed relatively often to keep the unit working. Overall, the first-generation Minis presented the most minor problems of all the generations.
In 2005 and 2006, Mini was moving towards the second generation; during these years, we saw a mix of the Gen 1 build and what was to become the second generation. These models present a complicated car for diagnosis, as each one we see has been different.
In 2007, generation 2 started. The Gen 2 Mini S and JCW were now turbocharged. The most common is the R56 hatch. Second-generation Minis had early problems with the plastic thermostat housings cracking and leaking. They also had plastic timing chain guides that
regularly broke. We have seen timing chains fail at 60k miles. And we have seen the same with the thermostats. There is also a plastic tube that runs behind the engine between the thermostat and water pump that is prone to leak.
The Gen 2 Mini is also prone to oil leaks. The main issues are the valve cover gasket and the oil filter housing. Other oil leaks are commonly seen in the turbo feed lines on the S and JCW models. The valve cover leak is an easy fix and likely will be done with preventative maintenance or replacement of the timing chain at around 60k miles. The oil filter housing on the nonturbo cars is a significant job requiring the removal of the exhaust manifold. On the turbo cars, it is only slightly more accessible.
Most Gen 2 Minis show major carbon buildup on the valves. And whether because of burning oil through leaking valve seals or, worn out turbos, or not addressing oil leaks, they lose oil fast. This engine only hold 4.2 liters of oil. When the levels get low, it can cause the hydraulic timing chain tensioner to not function, and engines can be damaged from jumped timing. At 100k miles, the valve train should be cleaned, and valve seals should be replaced.
Another issue affecting the Gen 2 and 3 Minis is clogged sunroof drains. When blocked, water drains down the A-pillar inside the car, often allowing moisture into the Footwell Module. Corrosion occurs either immediately or over time and will destroy the footwell module. This unit controls a lot of the car's electronics. Replacement requires coding to the vehicle with a BMW computer. Cleaning of the drains should not be done with compressed air, but with a specialty tool designed for this.
The 3rd generation Minis are showing much the same issues as the second. They now have more electronics and require BMW computers for most diagnostics. The 3rd gen cars have also presented a new issue. If not done perfectly, people have fried their footwell modules when changing the battery. It only takes a split second, but the cars will not even start when it happens.
Maintenance Tips
In closing, you need to do a few things if you own or are thinking about buying a second- or third-generation Mini.
Check your oil often. Every time you fill up is not too often.
Use only premium gas.
Keep an eye on your coolant level in the expansion tank. The thermostat is located above the transmission housing, you may never see a leak on the floor.
Do not ignore the check engine lights! Have them checked by a BMW shop. The parts stores can only read generic OBD codes. They do not tell as much as the BMW codes.
Find a local Independent shop that specializes in Minis.
Mini Models
R50: "Mk I" Mini Base & Cooper (2001–2006)
R52: "Mk I" Mini Convertible (2004–2008)
R53: "Mk I" Mini Cooper S (2001–2006)
R55: "Mk II" Mini Clubman (2007–2014)
R56: "Mk II" Mini Hatch/Hardtop range (2006–2013)
R57: "Mk II" Mini Convertible (2009–)
R58: Coupé (2012–2015)[62]
R59: Roadster (2012–2015)[63]
R60: Countryman (2010–2016)
R61: Paceman (2013–2016)[64]
F54: Mini Clubman (2015–)
F56: Mini Hatch/Hardtop (2014–)[65]
F55: 5-door Hatch (2015–)
F60: Countryman (2017–)