Hello, i have purchased a car and before paying...

We would like to inform you that in this regard, you may not terminate the contract of sale because you knew of the defect that existed. All you can do is to ask for compensation for damages caused by the seller's failure to repair the defect and failure to implement the terms of the agreement between you.

  Here are the provisions of the Civil Transactions Law related to your inquiry:

Article (237)

The right for rescission of the contract, under the option of defect, shall be operative in contracts, where rescission is likely to occur, without stipulating it in the contract.

Article (238)

The defect which makes the option operative must be old, affecting the value of the contract’s object, unknown to the buyer and provided the seller did not specify the discharge thereof as a condition in the contract.

Article (239)

1. If the defect fulfills the conditions mentioned in the previous article, the contract shall not be binding to the option holder before payment, and rescindable thereafter.

2. Rescission of the contract prior to receiving payment, with all what it entails, without need for consent or court action provided that the other contracting party has knowledge thereof. After payment rescission shall take place only by consent or by court action.

Article (240)

Rescission of the contract on grounds of defect shall result in returning the object of the contract to its owner and recovering what was paid.