I really don't know if it will help you, but I will put it here. I had a similar problem but in my case it was related to the version of syntastic, so a simple git pull
solved it. My vim configuration is somewhat canonical, so I will share that:
let g:syntastic_mode_map = { 'mode': 'active',
\ 'active_filetypes': ['python', 'javascript'],
\ 'passive_filetypes': [] }
set statusline+=%#warningmsg#
set statusline+=%{SyntasticStatuslineFlag()}
set statusline+=%*
let g:syntastic_always_populate_loc_list = 1
let g:syntastic_auto_loc_list = 1
let g:syntastic_check_on_open = 1
let g:syntastic_check_on_wq = 0
let g:syntastic_javascript_checkers = ['eslint']
When you open your file that contains some mistakes, it should show that into the error window.