My 2008 Toyota Avensis 2.0 D 4D TR was purchased in February and, due to a 'whoop' noise every time the clutch was used on start off, the Toyota dealership diagnosed a problem with the turbo and replaced it under warranty. It is now making the same sound again, albeit not all the time. It's mainly noticeable when pulling away, but nonetheless it's still happening on occasion. When the engine is started from cold, it is much quieter than when it reaches its operating temperature, and sounds like an old post office van when pressed, mainly at lower speeds. I have also experienced a variation in idling speeds in the past for no discernible reason, but the garage says they have checked all this out and that the engine is not noisy, and all is ok. Any ideas on the problem for me to take back to them? The mileage on the car is approximately 22,500. Also, what do you consider to be the quietest 1.6/2.0 diesel saloon/hatchback on the market at present?