I'm not sure where to put this because I don't know what it is, but it's been happening for a while...

Ok, let's say i turn out on to a 40mph road, then I accelerate up to 40mph, now to stay at that speed I have to let off the gas and just have a little bit of throttle for that constant speed, the problem is that when I only have a little bit of throttle I start to hear this kind of grinding noise, but if I push in the gas a little bit more it goes away, so it's only at small amount of throttle and usually lower RPM's, and I can't really explain the noise it makes but grinding is the closet thing I can think of, so if this has happened to you please help me out

 

This'll sound weird but my aftermarket muffler had been installed all jacked up from the previous owner and when sitting at idle or at really low throttle the vibration from the engine through the tubing would vibrate the metal hanger on the muffler against the rear frame of the car and sound like a grinding noise.

Might be something to look at.

 

It's coming more from the engine though with certain amounts of throttle

 

Automatic or manual? Would think if it was engine you would hear the noise all the time. My 700r4 made some unusual grinding/whirring type noise that seemed to be coming from the engine compartment shortly before it let loose. rear end noise can seem to emulate from odd places , have someone climb in the back seat and ride down the road.

 

I agree, try to track the noise down. The sooner the better, don't know if that vibration is a part thats about to fall off! Another thing, do you have a problem with the starter scratching during start up?

 

I'm not sure if it's the starter scratching but sometimes when I turn the key I get a really bad grinding noise and it doesn't start or turn over unless I take the key out and try again, and would the transmission only do it at certain RPM's?

 

Oh and it is a 700r4

 

Just checking, my flexplate's bolt holes had been chewed out and the flexplate was just sandwiched in there. Car ran and drove great, except for a vibrating noise when I got up to speed, like a loose exhaust clamp would make and the starter would scratch from time to time. Turns out I put the flex plate on backwards, D'OH! That's why I asked if your starter scratched. Just give your flexplate a good shove back and forth to see if it moves, shouldn't move at all, might flex a hair though. You just gotta get out and track the noise down, best way to find the problem.

 

I can't get out to see where the noise is coming from because I need to be driving when it happens