I have a 2004 6.0L V8 32V DDI OHV Turbo Diesel.

Today for the first time since buying it about 6 months ago, when I turned over the key, the engine wouldn't start. The low-fuel light is on, but there is still plenty of fuel, I think it turns on sooner, because the needle is not in the red.

Anyways, the starter sounds normal at first and then it gives off this swish sound (high winding noise, then it stops), after trying it for a 6th time, it eventually started. Then I drove it home, turned it off and also wouldn't start at 1st try, it started on the 2nd try.

What do you guys think this problem is ?

Thanks!