The phrase "groaning noise" refers to a low, deep, and often unpleasant sound that someone or something makes, similar to a long and heavy sigh. Full definition
Although our dark green Cherokee had fewer than 3,000 miles, the front suspension system made some kind of groaning noise when I drove it over rough terrain. (articles.orlandosentinel.com)
Some 2008 - 2011 Ford Focus vehicles may exhibit a whine, howl or groan noise from an intermediate shaft bearing with the vehicle in motion. (autoserviceprofessional.com)
The vehicle sometimes make a creaking or groaning noise during turning or driving over bumpy surfaces. (mechanics.stackexchange.com)