vehicle: 2007 mini cooper n12 engine
car came in with "death rattle"
we replaced the timing chain, guides & tensioner, changed oil & filter.
car ran fine, customer had car for 2 days, came back with "check engine" light on.
dtc: 2870 2891 287D
we found the vanos solenoid valves partly blocked with what appears to be oil filter element fibres,
we cleaned them & re-installed, road test produced the same dtcs.
swapped solenoids (int/exh), road test again, same dtcs.
swapped cam sensors, same result.
we ran car with crankcase cleaner additive & changed oil & filter again.
longer road test, same result.
we replaced the intake vanos sprocket, same result.
engine oil pressure is 32psi hot idle, 45psi hot 3000rpm.