Private purchase and rights

Good day am new here, hope someone can help me how the legal situation after a private purchase is. Have bought an Opel Corsa C 1.2 BJ 2005 private with contract. Now after 3 months about 2 times cooling water have been completely empty. Turns out that the heat exchanger is leaking. The driver’s room has become very damp. The cigarette lighter has been noticeably rusty for a long time. Possible to get a part of the price for the repair again? For answers very grateful. Greetings e