Engine Clicking And Tapping Noises problems of the 2016 Kia Motor Sportage

Our 2016 kia Sportage began emitting light smoke out of the exhaust. We became concerned and asked out dealer to look into things. The dealership said they needed to do tests (this consisted of filling the oil up and asking us to drive 1500miles) we did as they asked and pithing 700mile the engine started to make clacking noises and on 2 occasions lost power. We returned the car to the dealership stating our concerns, they wanted to repeat the test but we refused to drive the car. The dealerships communication was very poor, never replying to our calls or emails so we decided to contact consumer affairs. The first call was great, very supportive and informative. Said they would help and we would be totally covered. This is as good as things got, consumer affairs proceeded to repeat the same poor communication as the dealership showed and not reply to call and if they did take a call said we needed to speak to our case worked who was never in work that day. Finally the dealership said that the engine had sludge in the engine and it would need a complete replacement (this is a 3 yearly car with 60,000 miles) kia refused to honer the warranty as we didn't have enough service records (never stating what was enough) and now we are in the process of appealing and consumer affairs and the dealership are repeating the lack of communication with us.