Why is my Bosch dishwasher not washing on top rack

the unit could be un-level

top rack is for small plates & cups not pots & pans as they may obstruct the rotating of the sprayer & foul the water from getting to all the items

Hi, I have an older dishwasher also and recently my wife alsocomplained about it not cleaning right... so me being the man I am tried invain to clean the things... Bought new spray arms online and installed them inminutes...now the thing works like new... However I have also found that if theheating element goes bad then that also can mess things up bad... So I wouldbuy new spray arms, and also check out the heating element to make sure it isworking... Here is a tip that will help you with the online buying...
Dishwasher Spray Arms not Spinning

How to Buy Appliance Parts Online

A bad heating element causes many problems in dishwashers...

Dishwasher Problems The Heating Element not Working

Dishwasher Maintenance

heatman101

I took the bottom apart and found that the drain had alot of debris, it would drain but there was always some residue in the clean water. The bottom rack came out and I took the one washing arm out and the cover over the screen, problem solved.

is this a bosch dishwasher? if so then check my recent post about that here.
http://www.fixya.com/support/t1713479-bosch_dishwasher_top_row_dishes_not_get

After observing the water just gushing out when the spray arm was removed, we determined there was still a bunch more calcification/soap in the ends of the spray arm. (We have very hard water in our area). Unfortunately, you cannot open up the spray arms to clean them out, so it took about 30 minutes of pounding and manipulating to get all the gunk out. Now my dishes are clean again. Hallelujeh! And the water cleaning the dishes is cleaner, as well.

only the top rack isnt getting clean?
there is a little plastic circle in the middle of the bottom of the upper spray arm. turn it counter clock wise to pull the upper spray arm from the upper rack. make sure that isnt clogged and the spray holes are not clogged. otherwise....

the piece that the bottem spray arm plugs into and runs along the back wall of the tank to the top is called a feed tube. pull the bottom spray arm out. now you can see the part of the feed tube that feeds the upper spray arm water. does it pop out freely and easily? if so then you need a new feed tube, if not then its most likely your not achieving the right water level or your impeller connected to your circulation pump(motor) is clogged not supplying enough water pressure to travel up the feed tube to spin the upper spray arm.

Common problem, bad timer. Press Scrub Wash and Del/Econo at the same time and the cycle will end.

The dishwasher salt response is acceptable for Europeans, but U.S. dishwashers do not have a salt dispenser, nor is dishwasher salt sold in U.S. stores. U.S. consumers should descale their dishwasher using Dishwasher Magic, Lemi-Clean, Lime-A-Way, CLR, or vinegar until scale is removed from the machine, then add a rinse aid to the dispenser, which should prevent future problems. For very hard water, regular, periodic descaling treatments should be done. For the vinegar cleaning, place a full cup (8 oz) of vinegar in the top rack of the dishwasher. This way the vinegar is release throughout the wash cycles, performing a more thorough cleaning.