Basically, a couple months ago i started hear a kind of soft growling type sound from under the hood. Our first though was maybe a water pump going bad, so that as well as the rest of the pulleys were checked, no go there. After about 2 weeks, the noise got louder and we realized that it was really only noticeable in park, and even worse when parked on an incline.

Shortly after making that discovery, i took the car in to the local gm dealership to have it looked at. After 2 days i get a call with them saying there was nothing wrong with the trans, the noise being made from either some valve or something gone bad, or that my uppper intake was going bad. I went and retrieved the car and made sure i pointed out the noise to make sure they were hearing the right thing and was looked at like i was crazy.

After putting a new intake on the car, the noise was still there so i took the car back to the dealership again, and was again told they couldnt find a thing wrong.

Its now a couple months later and my fiance has been driving the car mostly, so i drove it the other day just to make sure it was alright. It was immediately noticeable that the sound had gotten quite a bit louder. After driving around for a few, i got caught at a traffic light, and upon taking off from the light, the car started bucking around a little bit like the converter was locking and unlocking. Then last night i was driving it again and come to another traffic light where i had to make a right hand turn. I came to a complete stop, then proceeded to make my turn. As i hit the gas pedal, the car began bucking around again. I had music on so i couldnt really hear anything, but it didnt feel like a motor stalling type bucking. The fiance said she has had that happen to her twice recently also.

Any idea what im looking at here?. I know the bucking sounds like a converter issue, but could that be my entire issue, or is a bearing some where within the trans trashed and metal shavings taking the converter with it? No codes have been thrown yet.

i think i would take it to a trans specialist rather than the dealer. have them drive it or go with you, a good one would