I recently purchased a GC CRD which is the first diesel I have owned.  The following problem I am about to describe has been determined to be a non-issue by 3 dealerships.  I would like to know what others have experienced regarding this matter.  
PROBLEM:  Upon deceleration from anything above 2K rpm my motor will rev down to 1.5K rpm and hold right there.  I can travel 1 or 2 city blocks before the weight of the vehicle plus engine compression will slow the motor down to 500 rpm.  When coming to a stop it takes quite a bit of braking power to quickly bring the motor speed down from 1.5K to 500K rpm.  I concider this dangerous, when coming to a stop.  I am use to a gasoline engine which easily revs down to 500 rpm when coming to a stop.  all the dealerships contend that this is normal for the CRD.  Is this true?
Thanks for any input.