I’ve been noticing that my 2012 Chevrolet Sonic rumbles when going over bumps. I have about 60k miles on it, could it be the sway bar?

When im driving on a paved/smooth surface the car is fine, however as soon as i go over a bump or pothole or even just a mildly rough stretch of road i start to hear a rumbling noise from the front of my car. Thought it was the shocks but theyre not leaking and i didnt check the sway bars. I dont know how to check those. Please help

My car has 60000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hi there. If the sway bar was at fault, the noise would also be present when turning and a possibility of excessive body roll when turning. The source of noise over bumps can be difficult to diagnose since the bumps affect the entire vehicle. Worn shocks could definitely cause some noise and do not have to be leaking to be worn or weak. There are also ball joints, control arm bushings, steering rack bushings, cradle bushings, etc..

A qualified technician with good eyes and ears should be able to determine the cause of your noise with a proper inspection. YourMechanic has several available technicians that can assist you with an inspection of the noise when driving over bumps and provide an estimate and direction of repair.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

Any unusual shaking or vibrating forces coming from the engine is cause for concern. It could be something as simple as old spark plugs producing an uneven power delivery, it could be something serious like worn or broken engine mounts, or it could be even more serious in the case of internal engine damage.
General Motors LLC (GM) is recalling certain model year 2012 Chevrolet Sonic vehicles manufactured March 1, 2012, to June 29, 2012, and equipped with a 6 speed automatic transmission and 1.8L four cylinder engine. In the affected vehicles, the transmission turbine shaft may fracture.
The Problem: The transmission turbine shaft may fracture as a result of a supplier quality issue, according to GM. If this occurs in 1st or 2nd gear, the vehicle would not be able to upshift into 3rd or 6th gears.
Tire issues: The most frequent causes of a vehicle shaking while driving stem from tire issues. Tires begin to behave differently when worn or out of balance. Tire replacement, realignment, and rebalancing are common solutions.
The most prevalent cause of vibration is problems with your wheels or tires. The potential problems include improper wheel and tire balance, uneven tire wear, separated tire tread, out of round tires, damaged wheels and even loose lug nuts.
They can last for 200,000 miles or longer, so the mileage of your friend`s car will help you determine how reliable it will be for you. Typically, newer cars are more reliable. If your friend`s Sonic is pretty new, it will last for much longer than a car that`s been around the block a few (thousand) times.
Clunking, humming or whining sounds are signs of automatic transmission problems. Faulty manual transmissions will also give off loud machinelike sounds that seem to come out of nowhere. A clunking noise when you shift gears is a telltale transmission situation. Have a mechanic look it over.
Strange Noises

If the sound resembles humming, buzzing, or clunking, you may be experiencing transmission failure. Bad automatic transmissions may emit humming, buzzing, or whining noises while manual transmissions have harsher “clunking” sounds.

The most common cause of engine sputtering are issues with the fuel system. These can range from bad fuel filters, fuel pump issues, or fuel injector issues.
Damaged CV joint: The most common cause of a clicking or popping sound from the wheels is a broken CV joint. The CV joints, which stand for Constant Velocity, are essentially the wrists of your vehicle`s steering system.
(i) Vibrations within the frequency range of 0 – 20 H z are called infrasonic vibrations. Humans cannot hear them. (ii) Vibrations within the frequency range of 20 H z to 20,000 H z are called sonic vibrations. They can be heard by human beings.
GM`s attempt to correct the “Chevy Shake” was through addressing an issue with the transmission fluid. GM recommends “owners replace the original transmission fluid with a lighter viscosity to correct the repair of the transmission and correct the shaking”.
Worn or dirty spark plugs can cause a petrol car`s engine to misfire in one or more cylinders, which can cause vibrations when the car is idling or at running speeds. The easiest solution is to replace your spark plugs and check the related wiring. Engine vibrations can also be due to the air and fuel systems.
What causes the Chevy Shake? The class action lawsuits named two causes for the Chevy Shake: a weak aluminum driveshaft and GM`s 8L90 and 8L45 transmissions. According to Kim v. Bostick, the aluminum driveshaft (known as a “propeller shaft” or “prop shaft”) weakens over time and eventually drops to the ground.
Worn or dirty spark plugs can cause a petrol car`s engine to misfire in one or more cylinders, which can cause vibrations when the car is idling or at running speeds. The easiest solution is to replace your spark plugs and check the related wiring. Engine vibrations can also be due to the air and fuel systems.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

I’ve been noticing that my 2012 Chevrolet Sonic rumbles when going over bumps. I have about 60k miles on it, could it be the sway bar?
ANSWER : Hi there. If the sway bar was at fault, the noise would also be present when turning and a possibility of excessive body roll when turning. The source of noise over bumps can be difficult to diagnose since the bumps affect the entire vehicle. Worn shocks could definitely cause some noise and do not have to be leaking to be worn or weak. There are also ball joints, control arm bushings, steering rack bushings, cradle bushings, etc..

A qualified technician with good eyes and ears should be able to determine the cause of your noise with a proper inspection. YourMechanic has several available technicians that can assist you with an inspection of the noise when driving over bumps and provide an estimate and direction of repair.

Sway bar dosent fit correctly need a custom sway bar the oil pan touches sway bar
ANSWER : Hello and thanks for your question. If the oil pan is touching the sway bar on the vehicle, you can get an oil pan that is more for performance that has a wider bottom but not as deep. By doing this, you will need to replace the pick up tube with a shorter one to fit with this type of oil pan on. This type of oil pan will give you the clearance you need and not touch the sway bar. If you need assistance replacing the oil pan then seek out a professional, like one from YourMechanic, to make this adjustment for you.

Rattle sound when going over bumps 2011 Chevrolet Malibu
ANSWER : Hello – I would try to replicate the noise with a linebacker friend or two throwing their weight on one front fender at a time. Your parts replacements thus far are the logical ones, and the ready-mounts (assuming they had new strut plates) should have eliminated the most common source (strut plate and bearing). Check control arm bushings and tie rod ends (both inner as well as outer). It’s also possible it is not a suspension component at all, but rather something on the chassis or a hub cap that vibration has loosened. For professional assistance, I recommend a noise inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

Hatchback needs sway bar replaced
ANSWER : Hello. There is only one front sway bar on the vehicle. The sway bar is connected on both ends with link pins. There are two of those so that may be what he is talking about. They should always be replaced in pairs so you may be hearing the old one making noise. I would have it replaced also if that is what is recommended.

Front end rattle when going over bumps in a 2010 Milan Hybrid. Also drifts left noticeably on flat road. Are the two related?
ANSWER : The rattle could be due to a loose or worn sway bar, strut, body panel, or other suspension component. As you are describing it, the noise sounds fairly obvious so a mechanic should have no trouble pinpointing the origin on examination. The pulling is caused by misalignment and among the possibilities are too much cross camber. That is, inasmuch as your car pulls to the left, the camber setting on the left side of the car is more "positive" (measured in degrees) compared to the right side and the difference between the camber settings, left versus right (that is the "cross-camber") exceeds 0.5 degrees. Excessive cross caster could also be a cause, as well as a vehicle thrust angle that exceeds 0.5 degrees, side to side differentials in tire inflation pressure, tire faults (belt separations) and so forth. What I would suggest is first schedule an inspection to get the noise resolved BECAUSE to perform an alignment check, and do an alignment, there can be no faults in the suspension. Consequently, if the noise turns out to be due to a loose or defective suspension part that must be fully resolved before the alignment can even be accurately measured. To schedule an inspection of the suspension, please request suspension diagnostic – noise and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Replaced sway bar links and bushings. Still making a clunking sound. Sway bar feels loose when pulled on and can hear the sound.
ANSWER : You should not be able to physically manipulate the sway bar. If you are able to do so, there is something wrong with the bar, the links, bushings, the attachment to the frame or other suspension components. Whatever the fault is, it should be fairly obvious on inspection. To speculate, it is possible that "aftermarket" parts have been used, ones that just simply don’t fit. Please feel free to schedule a sway bar inspection/diagnostic and the responding certified mechanic will get this resolved for you promptly and professionally. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

I put my car in drive but it won’t go but it will go in reverse what could be wrong
ANSWER : Hi There,
What you are describing may be a result of a faulty speed sensor, potentially low transmission fluid or a even a faulty transmission control solenoid. As your vehicle travels down the road, the computer analyzes data being sent by vehicle speed sensors and engine speed sensors. Based on this information, the Engine Control Unit (ECU), or the Transmission Control Unit (TCM), executes the appropriate upshifts and downshifts by sending a signal to one of several shift solenoids. These transmission solenoids have spring-loaded plungers inside them, which are wrapped with wire. When this coil of wire receives an electrical charge from the TCM / ECU, it causes these plungers to open, allowing transmission fluid to flow into the valve body and pressurize the desired clutches and bands. When this happens, the transmission changes gears and you continue down the road. The computer controls the transmission solenoid in several ways. If the vehicle is equipped with a dedicated Transmission Control Unit, it can open or close the hydraulic circuit using a direct 12v signal. In some cases, the Engine Control Unit (ECU) can control the solenoid’s plunger by turning the ground circuit on and off. When this is not working properly, this can cause a jerking reaction, a delay in shifting or in some cases may cause the transmission to hesitate in shifting gears. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your transmission.

I was just told that a tensioner or pulley could have caused my alternator to go bad and if not replaced could make the new one go
ANSWER : Pulleys do go bad because the grease in the pulley bearing dries out, the ball bearings and bearing races get pitted and then the pulley becomes noisy. Sometimes, the pulley will actually seize. However, it will be EASILY evident if a pulley bearing is bad. So, all you need to do is have them PROVE the failure to you. If the pulley turns SMOOTHLY with no resistance and there is no noise, then there is nothing wrong with the pulley. Tensioners combine a pulley with a "tensioning" mechanism. If the pulley on the tensioner is good, to check the tensioning mechanism, just ask the shop personnel how many pounds they are able to measure (using a Gates gauge) as "belt tension" with the tensioner installed. If they can measure an installed belt tension of at least 80 to 110 pounds on the serpentine belt, you are fine. As far as alternator failures, even if all pulleys seized, the serpentine belt snapped and all the accessory drives came to a crashing halt, such would have no effect whatsoever on the mechanical or electrical function of an alternator. Alternators are DRIVEN by the serpentine belt. All that happens when the belt disappears or pulleys seize is the alternator stops turning; there is NO possibility of damage to the alternator. Once you re-apply a new belt, or new pulleys, the accessories start turning again, just like before and the alternator produces current to charge the batteries. As noted, pulleys do wear out…worn pulleys do cause noise but all that is beside the point. Insofar as your concern, you CAN confirm if they are telling the truth by just simply having them PROVE the alleged failure to you. If they cannot prove it, or are unwilling to prove it (don’t buy the "insurance rules don’t allow you in the shop trick), then do not replace the pulleys. In the future, you can save a lot of money by having a repair like this, as well as maintenance, performed on a mobile basis. So, please keep us in mind and if additional concerns arise related to your current issue, please don’t hesitate to inquire further.