One problem related to engine rattling and whining sounds has been reported for the 2018 Hyundai Elantra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2018 Hyundai Elantra based on all problems reported for the 2018 Elantra.
When accelerating with moderate to heavy throttle input, the engine emits excessive pinging and rattles noises. It sounds like "spark knock". No matter what brand of fuel or octane I run the car on, the engine makes these pinging and rattling noises. I've brought the car to the dealership service dept. Twice so far to address this concern. I was informed the first time that they hear the noise, but cannot diagnose it because the check engine light isn't illuminated. On the second visit, they told me it is a normal noise for the car. Having owned a handful of vehicles over the years, this noise is indicative of spark knock. If the problem is indeed excessive spark knock, this can lead to catastrophic engine failure, causing sudden loss of all power. After researching the issue online and speaking with other owners, it is apparent to me that it is a fairly common problem with the 2018 Hyundai Elantra sedan. I would like Hyundai to investigate this issue and come up with a fix. This problem has existed since brand-new off the dealer lot. The car currently has approximately 4,000 miles.