Vauxhall, Opel Insignia, Astra 1.6 SIDI A16XHT squealing noise, PCV valve, Camshaft seal noise fix.

Recently my Insignia developed a squealing noise coming from the engine bay. The noise was coming from the camshaft seal and PCV valve located in the engine rocker cover. Due to the faulty PCV valve, the car was building up a lot of vacuum in the engine, sucking air through the camshaft seal. From reading on the web, this is a known GM fault that will happen over time in the 1.6 SIDI  A16XHT engine. In the USA, GM had a service bulletin regarding this issue on the Buick Cascada, which uses the same 1.6 SIDI engine as some Astra and Insignia here in Europe. In the USA, GM replaced the rocker cover free of charge. However, folks in Europe have to pay for the replacement.
In the video below, I demonstrate the issue and the replacement process