The introduction of the turbo era in 2006 signalled a real change in direction for MINI’s forced-induction offerings and divided owners who originally had their feet firmly in the supercharged camp. Could anything ever surpass that supercharger whine? Would bolt-on mods have the same level of impact? What power would be achievable from this brand new unit?
Tuning aside, Lohen has seen increasing numbers of Gen 2 visit our workshop, certainly for performance upgrades but also for a range of necessary maintenance and repair work to keep the cars running as sweet as a nut. Much like the Gen 1’s, the N14 and N18 engines have their own foibles with particular areas to pay attention to.
The nature of the direct injection is such that coking has probably been our most significant maintenance job. It’s common to see cars with between 20-30,000 miles on the clock showing the telltale signs of coking fatigue and we’re performing this service regularly. It’s so common we now advise our customers to factor de-coking into their regular servicing intervals to keep their MINI Cooper S and JCW’s happy and healthy.
Still raced hard today in the MINI Challenge and tuned up to the antenna with a variety of performance upgrades, the Gen 2 has plenty to offer however here are a few keys issues we recommend you look out for with your MINI engine.
Inlet valve coking on N14-engine Gen 2 MINIs typically produces symptoms such as hesitation, loss of power and erratic idling. The issue can bring up engine management lights typically seeing codes for super knock – fuel shut off, however, it’s very important to note that this code can appear for a range of other problems so full diagnosis is always recommended. Your MINIs engine is essentially struggling to breathe due to the build-up of carbon around the inlet valves. Left untreated, the cars’ performance deteriorates and can lead to serious engine damage such as piston failure.
High Pressure Fuel Pump (HPFP)
Generation 2 cars with the N14 engine can suffer from rocker cover gasket failure characterised by oil seeping around the spark plug area and rocker cover edges.
The standard bypass valve is plastic that has a delicate diaphragm that can become pinched. When it pinches the diaphragm a loss of boost and performance can be experienced.
Dipsticks are an important part of your MINIs running and can easily be overlooked. The plastic tip on the MINIs dipstick can become difficult to read from discolouration and brittle over time, occasionally snapping into the sump. If the dipstick does break it is essential that the parts are retrieved immediately because failure to do this can lead to serious engine damage. Alternative metal spring dipsticks are available from CravenSpeed. These follow the contours of the dipstick tube much freer and do not degrade and become brittle and allow for an accurate oil level reading.