Over the years, car manufacturers have worked at creating and modifying vehicle engines to operate quieter. This has been the primary goal of most vehicle engineers, and there is a whole network of engineers devoted to this called Noise, Vibration and Harshness NVH).
Vehicle noise can be caused by several things such as tire noise, wind around the window seals, drivetrain, and whistle from around the radio antenna, or even exhaust and intake noise. Noise is also amplified when specific frequencies cause resonances in the interior and the body. Engineers usually use acoustic cameras, accelerometers, dynamometers, and subjective impressions to identify and isolate where the noise is coming from.
What the engineers have done to try and reduce such noises is by using deadening mats, stiffen the chassis, using different interior materials, and changing the response and stiffness of bushings and other elastomeric parts. They can also rebalance rotating parts or tune the intake and exhaust differently.
However, once you purchase the vehicle, there are reasons you may be experiencing vibration noises. They could be squeaky brakes, squealing belts, or rattling interiors some of these things you can correct yourself, but with others, you have to go to Goldfarb inc to get replacement parts. Here are some of the noises you may experience and how to address them.
Vibration while braking
Vibration when braking is very common and easy to deal with. The cause for vibration when braking can be due to worn brake rotors, which can warp slightly, causing a pulsation through the brake pedal when you brake.
Once you notice this, take your vehicle to the mechanic, and they will measure runout in the rotors by using a micrometer; and if the rotors are too far out of spec, you will need to replace them.
Vibration felt through the steering wheel.
When driving and you feel your steering wheel vibrating, then there’s definitely a problem. This is usually tricky because different reasons could be causing the steering wheel to vibrate, such as an out-of-balance wheel, worm struts, or shocks that no longer handle the vertical motion from the springs effectively, which may cause cupped tire wear.
Vibration can also stem from worn wheel bearings, a problem that you may notice more dramatically when turning. These are rotating assemblies and may differ from drift steering angles or poor alignment. Most people think that worn suspension parts or poor wheel alignment are usually the cause of vibrations through the steering wheel. Still, vibration usually comes from a rotating assembly of some sort.
Alignment issues usually originate from a hard hit on a pothole or a curb, which knocks everything out of spec. A slight shimmy of the wheel or a pull to one side are all symptoms of excessive wear and alignment problems, but that's all different from vibrations. As we mentioned earlier, steering wheel vibrations are from tire or wheel issues, driveline issues, and motor mount problems.
FWD driveline problems
A half shaft and a CV joint about to fail may cause vibration on a front-wheel-drive car. The half shaft usually has constant velocity joints on the inside and outside, and it's the inner joints, in particular, that cause vibration, usually at specific speed ranges. It can be hard to nail down this problem, but it’s a sure indicator when the vibration worsens when turning but stops when the wheel is straightened again.
A sure way to determine a faulty CV joint is to roll down the windows, switch off the music and drive in a tight circle, listening for any clicking noises. Faulty or failing CV joints may also result in a spatter of oil on the inside of your wheel.
Suppose you feel that the vibration is coming from the rear of your vehicle, or you can feel vibrations through the floorboards and have ruled out the tires. In that case, the vibration on your rear wheels is usually due to U-joint, driveshaft, center joint, or differential problems. U-joint trouble will also be accompanied by a clunk noise when putting your car in gear, setting off the gas, or accelerating.
Noticeable orange gas around the U-joints is also a sign of dried joints that are almost failing. Differential problems stem from insufficient lubrication and are usually standard with an RWD limited-slip differential.
If your car contains a limited-slip rear end, it requires special gear oil to stop the vibrations. If you are not sure whether your vehicle is limited-slip or not, raise the back end of your car and spin one wheel. If your other wheel spins in the opposite direction, you don't have a limited-slip, but if both wheels spin in one direction, you do.
Vibration when the vehicle is idling
Most times, when your truck vibrates during idling, especially when in gear, it usually originates from exhaust hangers or other worn exhaust parts, failed, or damaged. This is enough to cause the exhaust system to shake and vibrate with the engine, and a rumble or booming noise can accompany it.
When the vehicle is idling, vibrations can also be caused by clogged injectors or worn spark plugs. Ensure to have your mechanic check out everything in your engine is running well.
Vibrations felt through the floor.
When you feel vibrations coming through your vehicle's floors, it could be from the tires and wheels. Usually, it ties to a tire that is starting to fail because of tread separation, a bent rim, or slightly out of balance. These vibrations may show up when you hit specific speed ranges and usually go away when you speed up or slow down and could get even worse as you accelerate.
If you are trying to determine why you are experiencing vibrations, remember, just like any other diagnosis, start with the simple stuff first in your process of elimination. You can begin by examining the tires and wheels, then work your way through the process from there. Alternatively, take your vehicle to the professionals, and they will make accurate diagnostics and repair your car.