Not streaming files or...

I have a very strange thing; I run a setup with Nginx(v1.4.6) as proxy and Tomcat(v7.0.62) on Ubuntu 14.04 LTS server

It runs fine for some time 10+ hours - and then out of the blue it gets very slow and at some time I have to restart Tomcat. Restarting Nginx doesnt help...

I saw in nginx error-log this:
2016/10/21 11:20:28 13866#0: *222384 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 165.225.68.61, server: 127.0.0.1, request: "GET /html/js/barebone.jsp?browserId=ie&themeId=berendsensweden_WAR_BerendsenSweden625theme&colorSchemeId=01&minifierType=js&minifierBundleId=javascript.barebone.files&languageId=en_US&b=6205&t=1476990611000 HTTP/1.1", upstream: "http://127.0.0.1:8080/html/js/barebone.jsp?browserId=ie&themeId=berendsensweden_WAR_BerendsenSweden625theme&colorSchemeId=01&minifierType=js&minifierBundleId=javascript.barebone.files&languageId=en_US&b=6205&t=1476990611000", host: "www.berendsen.se", referrer: "http://www.berendsen.se/skyddsklader"

I then tried local on the server to check what was responding:
>wget http://www.berendsen.se/skyddsklader
That gave me back some html. So Nginx is responding

>wget http://www.berendsen.se:8080/skyddsklader
Then directly to Tomcat port. That gave me back some html.

>wget http://www.berendsen.se:8080/html/js/barebone.jsp?browserId=ie&themeId=berendsensweden_WAR_BerendsenSweden625theme&colorSchemeId=01&minifierType=js&minifierBundleId=javascript.barebone.files&languageId=en_US&b=6205&t=1476990611000
Then trying to get file, and also directly to Tomcat port. No reponse....

I tried to stop all public traffic to Tomcat by stopping nginx and then try to wget file = same result; no file.

My proxy_pass conf:
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_read_timeout 120;
proxy_http_version 1.1;
proxy_set_header Connection "";
proxy_pass http://127.0.0.1:8080;



Im totally lost here - iv tried al kinds of things.

So I realy hope that some can help or point me in a direction.

BR/Bent