It's a 96 2500 with a 5spd and a stock HX-35. It has a strange metalic noise coming from the turbo when under a load. It won't duplicate the noise while sitting but as soon as you put it under a load the noise is there and it get's worse with a loaded trailer. It almost sounds like a loose washer on a bolt rattling. ??? We've been through the whole truck and can find nothing loose or broken, the turbo seems OK, it has a little in/out play (normal) and no up/down or side to side play. All the exhaust clamps are tight including the down pipe. This is a friend's truck and only has had the pump tweeked a little, the truck is used for hauling almost everyday, and the only thing I can think of that he may be doing bad to the truck is long periods of idling.<br><br>Anyone have any suggestions? I'm all out of them at this point. [undecided]<br><br>DB

 

Maybe bad bearings?

 

Not sure, everything seems to be spinning freely and the oil line isn't pugged. [undecided]<br><br>Dang thing has me stumped. ???<br><br>DB

 

May have sucked up a few penguins with metal collars on.

 

Check the catalytic onverter to see if the membrane inside it is not breaking apart, this noise will resonate through the exhaust, sounds like what you are describing.
Also, if the truck is a 4x4, when it makes the noise, grab the transfer case shifter and see if it goes away, this drove me crazy trying to find a rattle in my truck while all it took to fix was to go under the truck with a prybar and bend the spring to put a little more tension on it, noise gone.

Hope this helps

Rich

 

Darrell, Have you discovered the problem yet?<br>I was having the same type of noise - thought it was the turbo and it turned out to be a broken exhaust manifold.