This is in regards to your query posted on the website CarDekho.com, we would like to inform you that Fiat Grande Punto comes in both petrol and diesel variants. The two petrol variants are : 1.2 liter Petrol and 1.4 liter Petrol. The car is also available in 1.3 liter Diesel engine. You can use the given link to view more about Fiat Grande Punto.
Sir, if all the engineers are saying that there is a problem in Punto than they might be right, then you should test another Punto in same variant for that problem. If you feel the same problem in the other car also than the engineers are right. But if you won't found the sane in test vehicle, then there Might be a problem with your tyre or wheel or it might be a problem in suspension system. If the problem is with tyre, then it is a regular problem. But you are saying that the problem appears when it just jumps over a bump. By this, it is sounding as a problem with suspension system.