I was at a stop sign, when to accelerate and heard a loud CRACK or popping noise. Car seems to loose power after and when I turn car off and restart it, it sounds rough Idling. Also noticed when I turned the car off and opened the hood sounds like a hissing coming from under the hood. Just bought this car used a month ago😩 still under the 10 year 100,000 plus an extended warranty. What could this be!!??