Hi. I bought a 98 K1500 a few months back... it has been smoking more than usual, i replaced all the plugs and wires & the erg valve... Now, when I start the truck I hear this rattling sound from underneath, it sounds almost as if there is a screw or bolt bouncing around. After the truck has been running for about 1.5 - 2 minutes the noise stops.

I got underneath and checked it out, and the only thing I could potentially see was a weld came loose on the muffler. If anyone has heard of this before please let me know. I might take a video of it and post it later on today.

Sorry this video sucks - It's the first one I've ever made...


Thanks in advance

Tim

 

Well there is a TSB out that perfectly describes the rattling you hear

http://speedy.sh/zJNNp/conrodrat2.JPG
http://speedy.sh/u2kkZ/conrdrat.JPG