I am having continued issues on my website www.abbeymachinery.com

The site is quite media bulky but I have recently reduced this a lot and compressed a lot of the images and pdfs.

However I am still getting intermittent 503 errors on the frontend of the website and sometimes on the backend. Talking to the hosting company they are saying the site is hitting memory limits possibly down to the translation plugin on the site. I'm just curious if anyone has experienced this before and ho to fix this?