I have a 04 cummins, 210k, 100% stock, recently had my auto trans rebuilt, when I left their garage, my truck was making terrible, loud fire whistle noise. real loud. took it back in to them, they said it's the intercooler. never made that noise b4. truck ran perfect.
There is no smoke w/ whistle sound. very loud. sounds like coming from turbo.
truck has a code but haven't checked it yet. might be related. truck will not boost up it seems, ( I have no boost gauge). Truck won't go over 10 mph. would intercooler make that noise? they tore 1/2 the truck apart they said to install trans cooler. Who knows what the hell they did!!!! can anyone help???

 

Sounds like an inter-cooler too turbo pipe boot clamp that didn't get tightened up and blew a boot off.
Check all your rubber boots from the turbo to the intake for a leak.