When it comes to keeping engine vibrations in check, it pays to start with a solid foundation. And by that, we mean the frame -- the skeleton, if you will, of any road vehicle. A solidly built, structurally rigid frame resists flexing, bending, and transmitting annoying vibrations.
The addition of crossbars -- also called stabilizer bars -- is a common practice to help reduce automotive body flexing and make a vehicle stiffer overall.
Squeaks, rattles and buzzes often come from a loosely assembled frame and are made worse by wide tolerances on a car's overall construction. In the auto business, this is sometimes referred to as "fit and finish." That's a broad term that essentially means, "How much attention to quality and precision did the builders devote in the assembly of this vehicle?"
A poor fit and finish, coupled with a loosely welded and flexing frame, can make any existing engine vibration sound and feel worse.
Sometimes, to hunt down and eliminate engine vibration you have to go straight to the source. Our next engine vibration fighter is sure to spark some recognition among experienced wrench turners.
The Anatomy of Engine Vibration
NVH typically comes in two varieties: airborne, which you perceive through your ears; and structural, which you mostly feel -- through the vehicle's seat, steering wheel and floor pan.Airborne disturbances are generally higher frequency sounds in the 300 Hz and above range. Engineers counteract them either by eliminating them at the source or deadening them with sound-dampening material (inserted in door and body cavities).Structural disturbances take place at such low frequencies that they are felt (as vibration) more than heard. Auto engineers must painstakingly measure and try to mitigate unpleasant sensations drivers experience, as vibration energy gets transmitted to motorists' hands, feet and even the seats of their pants! |
