Hi this is my first post... I own a 2003 trailblazer and ever since i bought it 2 years ago it has had a problem with some rattling. The rattling begins under slow to medium acceleration around 2500 rpms and gets worse until about 3250 rpms or until the gear changes. It doesn't happen under somewhat hard to very hard acceleration (or maybe the engine noise just drowns it out). I think it might have something to do with the tachometer or the wires for the tachometer as it sounds like the rattling is coming directly behind the speedo gauges (definitely not coming from the engine compartment). I would post a video of it, but when i tried the sound didnt really come out very well at all so it wouldnt help. The rattling is worse when its colder outside and it lightens up a little when the engine warms up. Its a very annoying noise and any suggestions are appreciated... Also, if you have suggestions to fix the problem can you please explain how or lead me to another thread that will help me out... Thanks!