1. (Units) a unit of heat in the fps system equal to the quantity of heat required to raise the temperature of 1 pound of water by 1Â°F. 1 British thermal unit is equivalent to 1055.06 joules or 251.997 calories.
Quick Answer. A major factor that usually causes tire noise is the air chamber inside the tire. The large void that is filled with air acts as a giant resonance chamber. Thus, the tires are something like donut-shaped drums that generate a low-frequency hum when tires are rolling.
Sound: A âgrindingâ noise, or âpoppingâ noise, possibly in succession. When: While steering, almost always, and most notably when parked. Possible cause: Strut Mounts. This component lets the front struts ârotateâ in relation to the body of the car, allowing the wheels to steer. When strut mounts wear out, the bearings inside of them typically fail, making it harder to steer the vehicle and putting additional strain on the steering system.