Vibration at Low Speed, even in neutral

Got my TDI (1999.5, 5-speed) at 95K miles, just a little bit over a year ago. With 111K miles on the clock now, the car still drives as good (or bad) as the day I got it. I really don't care about the inconvenience of a broken door switch or failed key FOB, as long as the car is safe and sound mechanically.

Here is the problem. The car vibrates when travels at low speed (between 5mph and 15mph). This happens whether I am in a gear or not, with clutch pedal in or out. The best way to illustrate or duplicate this is when I am stuck in traffic on a slightly downward slope. If I push the clutch paddle to the floor, move the shift to neutral and let the car roll down the slope. Vibration starts as soon as I reach 5mph and disappear when I pass 15mph. The same thing happens if I let the car gradually stop, with or without using the brake. The engine idles smoothly when this happens and there is no abnormal vibration on brake or clutch paddle. The vibration is not horrible, but it is significant for anyone in the car to feel it. Any idea?

Thanks.

How are your tires? I had a problem with my rear tires 'cupping', which gave a rumble in the 10-20mph range. The tires would look like they have regularly-spaced flat spots along the edge:

What about having a tire store rotate the tires? If the vibration is still there, have the tires balanced.

I had a similar issue when I bought the passat. Rotating helped; balancing helped a little more. That was also when I found one rim was slightly bent.

Tony

Not the tires

It happens with both my winter and summer tires/wheels. I am pretty sure it is not caused by the tires or wheels.

By the way, I think the vibration was from the engine bay. Will bad motor mount trigger something like this?

Ah....maybe it's the 'slow-down shudder'. Peruse some of these (many) threads and see if they are describing what you are sensing:

http://forums.tdiclub.com/search.php?searchid=4623261

The fix is usually an adjustment of the IQ (injection quantity -- the quantity of fuel injected at idle) using VAG-COM.

Mods also seem to fix the problem....bigger nozzles, chip job...