[Vwdiesel] Vibration in 2001 Jetta Diesel

[RedMerk at aol.com]

To All:

I own a 2001 VW Jetta Diesel with 151,000 miles on it.  I drive approximately 
1300 miles each week as part of my job.  Now for the problem:

I have an intermittent vibration in the drive train or engine somewhere that 
at times is quite severe.  To give some idea of how intermittent, this past 
Tuesday evening, the vibration was quite noticeable from Columbus, Ohio to 
Dayton, Ohio.  After that, all the way to about 50 miles east of Kansas City, 
absolutely nothing but a very smooth ride.  Then just a small amount of vibration 
for about two miles, then nothing again.

The dealer and a local independent mechanic who is very familiar with VW's 
have worked on this for the last 90,000 to 100,000 miles and found nothing to 
cause the problem.  The tires have been checked and rotated numerous times, and 
balanced numerous times.  The tires have been changed once and are about 
20,000 from being changed again.  There is no abnormal wear pattern on the tires.  

The computer checks of the engine indicate no abnormalities in that area.  
All maintenance has been performed per the manufacturer's recommendations to 
include oil, filter, tire rotation, and belt replacements.  Fuel mileage varies 
depending on A/C usage and loading from 47 to 55 miles per gallon.  The highest 
ever obtained was 58, and the lowest or worst was 44.  The loading of the 
vehicle seems to have no affect on whether or not the vehicle vibrates.  Wind 
direction and "brand" of fuel seem to have the most effect on the mileage 
obtained.  Biodiesel gets me the worst mileage overall.  I cannot state with accuracy 
whether or not the difference in fuel "brand" has any effect on the vibration 
or not, but at times, the frequency seems to have been worse after fueling at 
a "cut-rate" truck stop.  That is something that I am watching closely at the 
moment.

The vibration will sometimes come on at odd intervals of maybe 10 to 20 miles 
and sometimes as noted above, there was nearly 600 miles between the 
vibration episodes.  The problem started at between 50,000 and 60,000 miles.  This 
vibration is quite noticeable in the steering wheel.

If anyone has any ideas, I would sure appreciate hearing from you.

Emmit Williams