Small Vibration

I've lately noticed a small vibration when travelling around 100 KPH. It's only there when I let off on the throttle, so basically engine is slowing the car down. It's very minor, but I don't remember it being there before. Car has newer tires / rims, brakes were done last fall, so I don't expect it's either of those. Cars has just over 200,000 km on it. I've just had the tranny checked for codes, and nothing shows in there.

1999 Regal
3.8 Supercharged

There are many possiblities. First it could be a tire slightly out of balance or it could be one of the CV joints starting to vibrate. I would have the balance checked first, cheapest, and then try the CV joints. It could also be a motor mount that is worn but I doubt it. Like I said start with the tires and move in from there.

There are many possiblities. First it could be a tire slightly out of balance or it could be one of the CV joints starting to vibrate. I would have the balance checked first, cheapest, and then try the CV joints. It could also be a motor mount that is worn but I doubt it. Like I said start with the tires and move in from there.

I was originally thinking tires, but I would think the vibration would be there at the specified speed, but it's only there when car is not under load. (If I'm on the gas, nothing, but foot off gas, then it shows up, foot back on gas, then it's gone again)

I've actually got it in the shop tomorrow. If I remember, and he's got it on the hoist, I'll get him to have a look at the CV joints. Are they easy or difficult to change on this car?

To replace the joints you will need to replace the axle shafts on the car. It can be done without too many complications but if you already have it at the shop and the joints are bad have the guy there replace them. A lift is a great help when getting to the shafts. Also have him check the control arm bushings they can cause a similar issue.

Shop says it's an outer tie rod end. Luckly they are easy to change. Will just need to get alignment done after.

Thanks for your input.