Technical Fiat Palio Shaking!!

[Rheta]

Hi
I have a problem with my Fiat Palio.
When I drive at a speed of about 90km, the car starts to shake alot.
It almost feels like a flat tyre!
When I let go of the petrol, it's better.
When it idles it also sounds like the spark plugs miss.
I replaced the spark plugs,but it's still not better.
What can be wrong?

 

[qisheng]

I think you shoud check and replace ball bearing of wheels .

 

[ruigong_china]

Do you check the dynamic balance of tyre?