Erradic idle when in Drive ...

1999 Passat 1.8T, Auto (Tiptronic).
Second owner, bought the car 2 months ago. (I live in Europe, car was imported used from Singapore)

When the car is in Drive and I am at a full stop, I feel the car trembling a bit (bit more than I think it should). If I switch to "N", or "P" the car feels VERY quiet and smooth, as if the engine is not running, but if I get into "D" again with my foot on the break petal, I can feel the tremble.

The mechanic of the dealer that I bought it from said that it might be the transmission so he suggested an additive in the transmission fluid in order to "smooth" it out. I do not trust the guy, so I have not done this yet.

Any ideas ?

-Andreas

my car idles rough when im sitting still as well. im gonna find out where the fuel filter is, cause it maybe getting clogged and sufficient fuel may not be getting to the engine.

I dont see how the fuel filter might cause might problem ? do you think it could ?

Any ideas here ?

I have a 2000 Passat with 1.8 liter turbo with auto trans. It was doing the same thing at about 25k miles. It turned out to be the spark plugs and cleaning out the throttle body that fixed the problem. The wizards at the dealership wanted to replace the battery and temp sender. This was their last guess that they made on this car. They left the drain plug loose on this same service. Three quarts of oil sprayed under the floor boards before I got home. I now have 45 k and it and still idles smooth.