my dad has a 01 dually with 4.10 gears and a 6 speed and it doesnt seem to make much power till it gets to 1800 rpm then its fine and pushing on it a lil and when pulling the turbo is screaming not whistling but sounds more like a scream any idea on the cause. we thought with the low gears it should boost quick but it doesnt feel to make power till about 1800 and higher.

 

check your boots that go to and from intercooler for a loose clamp or cracks. Just had my injectors put in at a local shop and the 'tard that did it forgot to tighten the clamp on the the boots that goes to the intake horn. it was howling like a tornado siren and didnt make any boost.