I'm sorry to do this, but this is utter and complete crap, and the result of a hugely misguided campaign by the pilots unions.
Three Pilots ( Yes, I mean that, THREE Pilots) have been directly responsible for filing 98% of these reports of fumes. All three work for UK airlines , two for a 757 operator, and one for a 146 operator. Now read that again .. 98% of all reports of oil fumes in aircraft cockpits have been made by THREE pilots)
This is the worst example of scaremongering that I have witnessed in my (long) career as a pilot, and the Pilots Unions involved should be ashamed of themselves for putting their name to this hoax. I have said as much to my Union Rep, in writing.
There is NOcredible , tangible or widespread evidence of oil fumes in the cockpits of aircraft.
There were two specific problems a long time ago. One involved overfilling of 757 engine oil by a certain big carrier based in heathrow ( since resolved) , and seals on BAE146 that have since been replaced.
JMC-man