Cold water only very slowly trickles into the washer. Hot water works fine. Cold water has very good pressure and volume at all other sources in the house. The cold water hose at back of washer is clean clear of bends. This is a stackable, (dryer above washer) about 3 years old.

There can be 3 reasons for this I will tell u the easiest way to test this first
Problem1)turn the water off at the blue tap fitting that is proberbly under your sink take the blue pipe off at the washer end and place it into the sink turn the blue tap back on if the water comes out quick then the problem is more then likely your cold water solenoid that is either slightly blocked were it fits to the washer,But if it doesnt come out quick then the other 2 problems are as follows.
Problem2)the blue tap that u turn the cold water on to the blue pipe undue the little screw in the middle of the tap and pull the blue fitting off now with a pair of pliers turn the square metal fitting that was under the blue fitting making sure that the end of the pipe is in the sink if it comes out quick then that is the problem the blue tap fitting is rounded off when ot should be square turn the water of and replace the pipe and turn the water back on the cold water should be better now.
Problem3)the blue tap that u turn the cold water pipe of at the copper pipe is blocked or it has a broken shut off valve inside it this will need replacing these are the only problems that it could be let me know if this is any help to u peter