I got this 2001 Jetta in 2004. Very loud, poor power. Hard to start until I cleaned out a part of an emission(eat your own exhaust) part. Just to get to the alternator is over $200 in labor, and labor to replace the alternator belt is $107, very hard to get to. IF this car would not break down so much, it would be good, 45-55MPG. I thought I would save a lot of money with this good gas mileage, but how much gas can you buy with a $1200 repair bill? I have not saved any money, and it is not dependable, I do not trust this car enough to drive it cross country.
The most common diesel problems we see are carboned-up EGR valves (cause of hard start when the cut-off valve in front of it sticks) and clogged intake manifolds, usually from cars that are driven stop and go for short trips - a normal expectation for a car to be reliable under all circumstances, to be sure, but diesels JUST DON'T LIKE IT! A bad mass air flow sensor will cause a loss of power. Many people have had their turbo replaced, ($$$) only to find out the MAF sensor was bad. Also, if the car is driven infrequently, at slow speeds, the waste gate linkage seizes up, preventing the turbo from operating properly or at all. These engines do their best when they are given a chance to stretch their legs now and then....take 'er out on the highway. Because of the placement of the injection pump, the alternator is hard to get to, I'll give you that, but the labor to replace the alt belt (which operates P/S as well) seems excessive.