I recently had a sharp whistle on acceleration. My mechanics tells me comes from the ventilation hose being broken/spit and air is squeezed out causing the sound. The part is €25 but I have been told the replacement can be 5 hours due to the oil pan needing to be removed to get to the hose. The question I have is what else would make sense to replace while the area is accessible (e.g. other hoses in the area, cleaning nearby parts etc. ). I will summarise / list any suggestions into a final reply to serve for future similar jobs.