Groan on accel

Not sure about this one. 1999 3100, 88k. Maintainance kept up extremely well. On accelleration, I get a groan or a grindish noise..sounds pretty metallic and worse when cold. If I roll on the throttle it isn't so bad, its the punches that its horribly noticable. Sometimes when coming off highway cruising speeds, esp. letting off the throttle suddenly, I'll get it again.

I originally thought motor mounts, but I unbolted (and have swapped with another 3.1s) the top dogbones and tossed the engine around to see if it'd replicate..no such luck. I'm thinking suspension noise next, but then I remembered my sister's 1997 Grand Am is having a similar, though vastly different, problem. Same conditions except hers is a metal grinding that can give any mechanic night terrors for weeks, and we know hers is somewhere in the transaxle.

My concern is I might have a similar problem. Any heads out there form any ideas? I'm due for a transaxle fluid change in about 3k and I have some TransTune I can run through just to see if it makes a difference but...I'd like to see what you guys conjure up. Automatic transmissions just aren't my basket, and manuals are just barely.

The front struts are known for some weird noises on ours, mine grunt and moan in the cold weather, usually when you punch it from a stop, or or let off suddenly, like you described, and it gets less severe the farther I drive. In warm weather it doesn't do it at all.

Does your sound just last the duration of the body squat from accel/decel or longer than that? When mine first started doing it, I thought it was a motor mount or something too, until I noticed I could sometimes hear a moan or grunt from the left front strut when I get out after driving.