[Tom W]

An experienced Porsche mechanic can and will do it without engine removal. However, consider the mileage and age of the car and service likely to be required in the next 12 months when deciding which to have done. With the engine out, you can have a lot of minor stuff checked, cleaned and fixed that would be a major pain otherwise. Engine tin clean-up, spark plug and wires changed, power steering pump belt checked/changed, etc. You are going to be spending a bunch in labor on something you don't want to repeat in 6-12 months. Your car is 14 years old and it needs some attention simply due to age, regardless of mileage.

The noise is loudest at idle and not all that different while driving. Some have described it as a cement mixer sound. I have a cabriolet and it's 80 db inside the car at 60 mph with the stereo off so I don't care too much.