4.3L V6

[lbrough]

The 4.3 liter V6 in my new Silverado 1500 has a terrible "death rattle" or knock when it hits 1500-1750 rpm under even a light load (as when the truck is empty). It doesn't exhibit this noise when the engine is cold or at idle which makes me suspect the fuel-air mixture. I have taken it to two different Chevy dealers who have failed to come up  with a solution. Premium fuel doesn't help either. Any suggestions?

[Ranger Dave]

Could be exhust related.  Mine 4.3 rattles the exhust around 1400 rmps.  The exhust is poorly hung on the 4.3 and GM knows this.  There have been lots of complaints.  The dealer hung weights off of the exhust but it seemed just to rattle harder.  

What year is your truck?  How namy km's on it?  Just interested.  Its hard to find people with a full size V6.

[C1500]

Mine has had a problem with "Spark Knock" since new (150,000 on it now). The Dealer wouldn't do anything because "The check engine light wasn't flashing". I just turn the radio up.