Washing machine stand pipe

vandriver

Hi,I'm having problems lately with flooding of my kitchen floor,and am looking for help/advice.
To describe the set up,there is a wm stand pipe level with the counter top,which is about 30, cm tall,going into a 90° joint,to the waste water pipe that drains outside.
Also connected to this almost horizontal waste pipe is the sink,through a U bend.
My problem is that I am getting(I assume) air locks in the pipes,as sometimes the sink won't drain at all until you plunge it a few times.Also the washing machine waste water sometimes overflows the top of the standpipe and floods the kitchen.
When the washing machine empties you can hear a lot of gurgling in the sink,and sometimes air bubbles coming up,and when you empty the sink(when it does) you can hear gurgling in the standpipe.

Any ideas?
(If I need to include a diagram or photo please say)

scudo2

Blockage in pipe. Try Mr. Mucle

vandriver

A cocktail stick had lodged at the L bend,and collected years of hair and gunge around it!