I just had this problem with my 99 E300D. The car is almost out of warrenty so I took full advantage of the warrenty. The dealer replaced the nozzel assembly and everything is back to normal. The dealer told me it does not take much gunk to make the nozzle not shoot correctly. Next time I will try an air hose as the car will be out of warrenty. Ya'll have a good day and thanks for all of your advice.