Intermittent apache crashes and WSOD

Our Apache server has intermittent crashes. Sometimes 500's but also Intermittent "White Screen of Death" and a consistent WSOD everytime Apache is restarted. We can ssh "service httpd restart" to get things back. To get around the WSOD after restart we "wget https://servername.com/wp-admin". Nothing is showing up in the error logs that point at anything specific.
We are running WPMU.