Volkswagen Golf: Servicing problems

My wife has a VW Golf Cabriolet Convertible 118TSI, which we bought brand new in late 2012. We have had some issues with oil usage on this car, and have had to accept that it does use oil, as the dealership continues to tell us its oil use is within spec. It needs topping up at least three times between services. But in March this year, five months out of warranty, it went into limp mode and the 'check engine' light came on.

On checking check I discovered a fault code associated with the intake manifold shutter.

The dealer advised us that a new intake manifold needed to be fitted. The total bill, including a $165 "diagnosis fee", was a little over $1200. My attention was elsewhere at the time, so while we grumbled about the bill and that a new intake manifold was needed on a 3 ½-year-old car with 40,000 km on it, we paid it and moved on.

Last week it went into limp mode again, and after checking with a scanner, we came up with same fault code. Initially the assistant service manager advised me that they normally charge (another) $165 "diagnosis fee", however they would waive it this time.

A day later, we were advised that the new intake manifold is faulty, and that a new one would be fitted with no charge. So far so good, but we were then also advised that there was a fault code related to the timing belt. This would necessitate, we were advised, pulling the engine down, and another "diagnosis fee". This time it would be $660.

Before I could say any more, the assistant service manager indicated that they would fit the new intake manifold and recheck the car and any fault codes, before deciding if any further diagnosis or work was required.

All being well, the intake manifold will be fitted in the next day or so.

Whatever the outcome on the timing belt fault, I am certainly not going to pay $660 for a "diagnosis fee", nor will I have that dealership do any more work.

Whilst we await the outcome of this matter, we have decided two things as a result of this experience, and particularly in light of Volkswagen's issues with the DSG gearbox and emissions debacle. First, our Volkswagen experiment is over, second, we will do our level best to convince others not to buy a VW either.

What do you think of "diagnosis fees"? Are they the new norm within the industry, or is it a Volkswagen creation?