I was driving my car and the engine started knocking and when I stopped the car kept stalling and losing power especially going up a hill. I had oil in the car. I bought the car to a repair shop and the mechanic advised me to go to Hyundai because theyare having problems with the engines in the Tucsons. I found out they extended the warranty from 100k to 150k so Iam covered I thought. They started diagnosing my car and they said the engine needs to be replaced. They contacted Hyundai corporate to dis cuss this. Corporate said theyare no t responsible for this because there was sludge in the engine. The car has 103k miles on it. The diagnosis charge I owe so far is about 400.00 Hyundai corporate wants further diagnosing of the engine. The dealership said Hyundai corporate said I have to pay the additional diagnostic charges of approximately 900.00 before theyall determine the outcome of my claim. I donat think itas fair at all. I believe they should be paying for information theyare requesting. Iam having a hard time with Hyundai corporate with this runaround theyare giving me. I do t l ow what else to do? I canat afford to pay for an engine replacement that they should be responsible for this problem. I hope Iave proved enough information. Thank you sincerely.