One problem related to engine rattling and whining sounds has been reported for the 2012 Hyundai Veloster. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Hyundai Veloster based on all problems reported for the 2012 Veloster.
Purchased car on 5/5/2012 with 6 miles on it. Within less than a week and 200 miles the transmission began clicking. Took it into Hyundai and they stated it needed a new transmission. After 2 1/2 weeks the transmission was replaced as Hyundai refused to give me a different car. Since then the car cannot accelerate, sounds "clunky" and when going at low speeds sounds like the gear isn't engaging and sounds/feels like it would if you released a clutch too early. Car loses power and sounds like it's about to die. A hissing and rattling sound under the hood happens as well. After taking it in to dealer, dealer states they could not find the sounds or noises or loss of power I was having. Rpms rev really high before engaging in first gear. Dealer still won't do anything since they can't diagnose it. I have almost been in multiple accidents for failure of power and car not accelerating. Takes about 3-5 seconds before it goes. Brakes grab too easily as well. Loss of gas mileage (around 6-7 mpg) was reported to dealer but dealer told me it was due to "winter gas. " I can understand 2-3 mpg difference but 6-7 is too much. Car has also been in the shop for a week for the car alarm going off constantly for no reason. A piece of the windshield plastic also fell off for no reason when car was 3 weeks old. Dealer duct taped that part down until a new part could be ordered.