It has been few years, but I think WALJON is right. You can spin it by hand, but you should feel it.

 

[quote=WALJON;6026135]Maybe that was the wrong way to state that. It should spin freely by hand with no binding/grinding. There should be a little resistance. If it's bad you'll know it.

The best way to find the noise is with a mechanics stethoscope or something similar while it's running (chunk of wood, screwdriver ect).

 

thanks to all those who responded! i changed the vacuum pump and all is well again. *smile* as you might have guessed, i am new to the diesel world and am loving every second in my "new" truck...except yesterday. =)

 

Check your air lines off the vacuum pump and even down to the little lines that go to your heating duct doors. Repair as necessary. The vacuum pump generates a pretty good vacuum and sucks dust and sand into itself which will kill it within a year if dirt is getting in there. A vacuum pump will last indefinitely with no dirt intrusion.