shaking??

if it doesnt shake all the time its not your tires. its under acceleration when it shakes? what does that mean? when youre making your engine do more work the car shakes. motor mount? do you have a CEL light on?

when i was experiencing that, it was because the input clutch plates on my tranny were warped. it's probably just starting, and may not even be your issue. but either way start saving cause that cost me 1400 to fix.

sounds like you may need spark plugs and wires, as you accellerate this increases the demand on your spark plugs and wires, if thet are worn out ( as they do) your engine will begin to miss. this causes the engine to vibrate, when you release the gas , Other items that WILL need to be checked are your ignition coils and module, these control your spark delivery. . In my experience the coils tend to give out. There are three.

All of the answers above are valid options as they would all produce your symptoms. Maybe you would like to expand on those comments? I will throw one in there too.. Since it is on acceleration.. Maybe even a bad CV axle.

i would go with a broken motor nount

1995 grand am 3.1 179000. I understand what the original ppost is about as I have the same issue. . When driving at a constant speed and i wan to pass another car i hit the gas and it starts to shake violently until i ease up on the gas. now i have done a few things differently to try to get it to stop and it always happens when the trans is in overdrive at a constant speed, when driving in 3rd at a constant speed and i hit the gas in the same way it does not shake. i believe it maybe a problem with the overdrive .

If you have the ability to take on the task to look at the car yourself or have a knowledgeable person inspect the car. Check the CV joint. Opon acceleration the cars shakes but coasts fine is a clear indication of a bad CV joint. The CV joint may appear fine and the boot may be ok. If you look inside a CV joint, there are 3 main bearings that ride on needle bearings. Those needle bearing will go bad and fall out leaving the main bearing unsupported. This will cause a bad vibration during acceleration. Never judge a book by its cover when inspecting a CV joint. Before you believe anything you read on forums, look into the little things first. Many shops take advantage and will tell you anything.

Same thing at and idle or when accelerating but once I hit a constant speed it seems to let up. Changed plugs and wires. . . engine light flashes, when at constant speed it just stays lit until I try to speed up then it will flash again

im having same problem^^ did you fix yours? what was wrong?

Just fixed the same problem on my 04. It was the CV axles.

2004 Grand Prix gt when I go in between 60-70mph my car shakes but when I go under that speed or over 70 it stops any ideas ?

It could be as simple as wheel balancing. I had the same problem - had to change my CV shafts (the bearing that goes into the transmission had some teeth missing - "said in non-mechanical terms)

Yes i have a 2003 grand am gt my front left tie pops when u turn to deep while drive what can that be n when i pick up speed the left front side bounce

I replaced both cv axes still vibrates when accelerating, could it be the struts?

Mine happens intermittently while driving. Not accelerating or braking. I will turn the steering wheel in a corner and vibration happens even when I hit the straight stretch. Or it vibrates and I turn the steering wheel a little and it goes away. Or I just go down the highway and it happens and then goes away. Tires have been balanced and rotated. Still happens.

Yes I have had the same problem before and it was the CV Axle

Would my issue be the motor mounts? Feels like tire balance issue, but when I let off the gas, it smooths out. I just got the car, but the seller said someone worked on the exhaust, said it needed a motor mount, but to just drive it till it breaks I don't want to do that.

Adding that it is not a violent shake as stated feels like a tire out of balance but when you let the gas off it goes away. The follow said the guy that fixed the exhaust said it needed a motor mount so would that cause it and make it feel like wheels out of balance?

Tp clarify some of the shaking problem. I have a 2003 Bonneville non-supercharged, just regular engine. I think it's the motor only that shakes. When I am "cruising" about 45- 55ish (meaning casual acceleration only) mine shakes. But if I accelerate harder or let off the gas it doesn't shake hardly at all. I know out of balance tires and this does not fit the bill of that. Besides, tires have been verified numerous times and are brand new (didn't change when new tires put on) Here is what I have done, no change. - Checked motor mounts. Good! - Tuned up engine about 150K (first time). Now has 160K so newish plugs. Haven't pulled them to read them -- yet. That is next. - Tested the spark. Is solid spark on all cylinders. - Replaced plug wires (brand new) - Zero engine codes. No misfires, nothing. - Tried locking trans into 3rd gear about that same speed. Same problem with casual acceleration, goes away when you harder accelerate or let off the gas Problem still exists.and I really think it is engine related. A side problem. I have the hard shifting problem in the transmission. I found right after I had it tuned up at 150K the hard shifting problem was dramatically reduced. However now at 160K the hard shifting problem is back (trans gets hot, sensor switch needs replacing that is inside the tranny) and it will sometimes hammer between gears when it appears the engine seems to need more persuading than it used to need to get going. Too cheap to have someone tear off the trans to replace that switch.