Ben bu kodla ilgili yazının altına benzer taxonomiye sahip yazıları listedim.
Bununla çalışarak bir yere varabilirsin.

<?php
		//for in the loop, display all "content", regardless of post_type,
		//that have the same custom taxonomy (e.g. genre) terms as the current post
		$found_none = '<h4>Benzer İlan bulunamadı!</h4>';
		$taxonomy = 'mahalle';//  e.g. post_tag, category, custom taxonomy
		$param_type = 'mahalle'; //  e.g. tag__in, category__in, but genre__in will NOT work
		$tax_args=array('orderby' => 'date');
		$tags = wp_get_post_terms( $post->ID , $taxonomy, $tax_args);
			if ($tags) {
				foreach ($tags as $tag) {

    			$args=array(
    			$param_type => $tag->slug,
    			'post__not_in' => array($post->ID),
    			'post_type' => 'ilanlar',
    			'showposts'=> 4,
    			'caller_get_posts'=> 1
    			);

    		$my_query = null;
    		$my_query = new WP_Query($args);
    		if( $my_query->have_posts() ) {
    		while ($my_query->have_posts()) : $my_query->the_post(); ?>
	    		<div class="four columns listing">
		    		<div class="post-container short">
		    			<?php echo get_the_term_list( $post->ID, 'tip', '<span> ', ', ', '</span>' ); ?> 
						<?php echo has_post_thumbnail() ? my_get_image() :  my_get_image_blank();?> 
						<h5><a href="<?php the_permalink();?>"><?php the_title();?> </a></h5>
						<a class="small button" href="<?php the_permalink();?>">&rarr;</a></p>			 
					</div>
				</div>
    		<?php $found_none = '';
    		endwhile;
    		}
    	}
    }
    if ($found_none) {
	echo $found_none;
	}
    wp_reset_query(); // to use the original query again
    ?>