The tractor is now half way through its 13,500 mile service interval. As I’ve mentioned before, I don’t believe that oil can maintain useful levels of lubrication if left in an engine for that kind of period. I’m also extremely aware that the turbocharger shares the same oil supply. As such, I change oil twice as often as BMW recommends.

BMW’s oil filter kit is good value. A little over £5 gives a new filter, sump washer and filter seal. A classic last minute Halfords oil purchase was significantly worse value: a little over £90 for only 8 litres of Magnatec diesel 5W30.

I also had trouble changing the filter. E36 M3s have a metal casing clamped together with a 10mm headed bolt. The E46 330d has this plastic casing held with a plastic moulded 36mm hexagonal lump.

As I don’t own a 36mm socket, in the past I’ve managed to operate this with an adjustable wrench, but in this case it would appear that a BMW technician has overtightened the container at the last official service. Still, I’m a great believer in having the right tools for the job so another £10 of overpriced 36mm socket at Halfords and the job was done.