Alright, my boss gave me his "old" truck. It's an 04 duramax 2500hd with allison. Big step up from my old 99 gasser with manual windows, non-functioning a/c/heat/wipers/taillights and the unopening pass. door and non-locking doors. Comfy seats too. Anyway, had it for about 2 weeks now and I'm filling it up ALOT! I hand calculated the mileage the last time and I'm getting 10.something. This is about 50/50 highway street driving with a rather empty utility bed on the back holding maybe 100 pounds of misc fittings and 2 fiberglass ladders. It's 2wd as well. Oh it's got 43k on it. Also, it's got a a funky rattle. When letting off the gas and driving at any speed (noticeable below 35) it has this loud rattle like sheetmetal rattling on something. I was thinking maybe something with the exhaust but who knows. If the window is down it sounds like it's coming from directly below the door. Is there a heat shield or anything that commonly rattles that can be tightened? It's pretty bad when people walking down the street lookover to see where the heallacious noise is coming from
could be the cat. converter coming apart making that noise. What size tires are on the truck, that would alter your mileage. You'd actually be getiing better than what youve hand calculated. And, how heavy is your foot?
My foot is a feather weight on all my trucks... Tires are stock as near as I can tell, they are the same size or a tad smaller than the stockers on my dodge. The noise was REALLY bad this morning when I pulled it out on the street from the driveway, it was constant the whole time.
