late 99 f350, 6spd. 264,000 on it. Seems like it runs good. When I turn the key to start fuel pump seems loud but not terrible. When the truck is idling I can hear a loud whining from somewhere, It seems to fluctuate slightly and Im wondering if that is just the fuel pump working too hard or a bigger problem like HPOP. After I shut the truck off and restart it when it is still hot I still hear the fuel pump but there is a high pitched whining that comes on at the same time? And only when its hot. Dont really know what is causing that? Hopfully some of you powerstroke whisperers can help me out.