hey y'all. ive noticed in the last few days, when i start rolling from a stop or when im going about 40ish in a higher gear, i notice a slight vibration/growl(its so slight, if somebody else drove my car, they probly wouldnt notice it). i thought maybe my tranny fluid was low, but i checked that. Could my plugs be going bad already? ive got 68,xxx Miles on it now. it runs fine in higher rpms. i've also got a replacement fuel filter, im going to replace it as soon as im able to(cant do much right now due to a recent back injury).
any opinons on what it could be? or am i paranoid maybe?

Where do you hear the growl, sounds like a wheel bearing.

when the engine is under a load(under initial acceleration, around 1-2grand on tach in OD. as far as i can tell, theres no change in sound when i turn. it may be my bearing, when i had my inspection, the dood at autotire said to "keep an eye on it, it is starting to wear out". i thought he just was fishin for a bearing change joerb. :? any way to physically check for myself?

It will growl when you accelerate and the tone will change with the speed.The faster you go the higher pitch when you decelerate lower pitch.Follows rpms

m'eh. i dont think thats it. it stops vibrating at higher speeds(which is why i think its an ignition/fuel thing) and what i call a growl(it really just has a lower tone when accelerating)disappears at higher rpms/accelleration. i noticed that it was ideling slightly more rough at a stoplight tonite.

This has nothing to do with your plugs. Even if they were the issue, it would be a misfire and it would be a repeated, cyclical type of thing at all times. Sounds like something rotational either in the driveline or in suspension. I.E., wheel bearing, CV joint(*), etc.

Wheel bearings on GM cars are pretty easy to replace. They are all a one piece sealed setup that you just undo the 4 bolts and replace with a new assembly.

And as long as the fuel rail is pressurized, it isn’t a fuel issue, otherwise you’d have misfires resulting from cylinders not getting adequate fuel. You’d know if your fuel rail wasn’t pressurized because the car would be extremely difficult to start, if at all.

When was the last time you cleaned your intake? All the way from the airbox to the TB and MAF?

Your description sounds like the noise I have started to notice over the last week from my alternator (rear) bearing going. It is noticeable at idle (kind of like the sound of a power steering pump going but a little less "whiney"), the sound increases in pitch just a little on initial acceleration but then gets progressively less noticeable to inaudible at driving speeds.

Pop the hood and see if you can zero in on the noise, perhaps while you throttle up a little. My 2000 SSEi has 145,000 miles on it so it'* no big surprise that it is time for a new alt.

i noticed that the vibration only occurs when accellerating/ideling. im goin to pop the hood today.

i just changed my fuel filter and there was black crap coming out. that might have been the problem, ill find out shortly when i drive it.