GMC Sierra is a popular truck brand in the United States. However, one of the most common problems GMC owners report is their GMC Sierra shaking when they drive. Vehicle shaking is not an issue only for GMC Sierras. In fact, every type of vehicle can develop a shake at some point in its lifespan for various reasons. A vehicle that shakes is usually indicating that there is something wrong with the vehicle that needs to be addressed. Shaking is merely a symptom of a large issue. The issue could be quite inexpensive to fix or very expensive depending on what the core issue is that is causing the shaking.
Why does my GMC Sierra shake?
A shaking GMC Sierra is an indication that there are issues concerning either the tires, wheels, axles, suspension, steering components, spark plugs, spark plug wires, fuel pump, fuel injectors, brakes, the engine, or the transmission.
Since there are so many different potential causes of a shaking vehicle, how does the owner know where to begin to fix the problem? The best thing you can do is to take your vehicle to a repair shop immediately once you begin to notice the shaking. A certified GMC technician or mechanic will easily be able to help identify the core issue and give you options for what kind of repairs need to be done to fix the problem.
However, if you would like to fix the issue yourself, the biggest clue you have to pay attention to when figuring out the root cause is when the shaking occurs. Depending on when the shaking becomes the most pronounced, it could help determine whether the cause is coming from a problem with the engine, transmission, brakes, wheels, axles, tires, or a different component.
Vehicle shaking is not an uncommon occurrence in many types of vehicles. That is why there is so much information and resources available online for motorists to access to help them make determinations about what could be causing the problems.
When it comes to the GMC Sierra, GMC has its own resources available that common detail issues that cause the truck to shake. Additionally, GMC owners have published their own personal accounts of how they fixed their GMC Sierra when it started to shake.
Let us take a look at both the GMC recommendations as well as the private owner’s personal experiences to identify some of the most common root causes of a shaking GMC Sierra.
My GMC Sierra shakes while it is idling
The typical GMC Sierra, if properly maintained, can easily last up to 200,00 miles, with some reaching even 250,000 or 300,000 miles without major problems. Aside from the regular maintenance, a GMC requires, like oil and oil filter changes, tire rotations, air filter replacements, transmission and coolant system flushes, etc. a major part of properly maintaining a GMC Sierra is addressing minor issues before they become larger issues.
If your GMC Sierra begins shaking when it is in “park” and idling in your driveway, you will want to fix the problem immediately before it turns into a major problem that is more expensive and requires more work.
Here are some of the most common problems that may cause a GMC Sierra to shake while it is idling.
Ignition system issues
The ignition system of a GMC Sierra consists of spark plugs, spark plug wires, and ignition coil packs. These components are responsible for creating a good spark to ignite the air and fuel mixture that enters the combustion chamber of your engine.
If any of these components are bad, it could cause your GMC Sierra to idle rough and your entire vehicle will shake.
Although there are many recommendations about when spark plugs should be replaced, a good method is that your spark plugs should be replaced at the 100,000-mile mark and then every 30,000 miles after to ensure that you are getting proper spark to your combustion chamber.
If your vehicle is shaking, it could be an indication that you need to change out the spark plugs because they are corroded and are either misfiring or they are creating an inefficient combustion spark.
Spark plug wires
Spark plug wires should be replaced at the same time that the spark plugs are replaced. If you inspect your spark plugs and they are still in prime condition but your GMC Sierra is still idling rough, you may want to see if your spark plug wires have gone bad.
Ignition coil packs
The ignition coil packs help to tell the computer and the ignition the best time to create the spark to turn over the engine. Any misfiring and/or rough idling could also be a sign that the ignition coil packs need to be replaced.
Bad timing belt
When a GMC Sierra shakes while it is idling, it could be a clear indication that your truck may have a bad timing belt or timing chain.
Bad motor mount
A worn-out motor mount can cause a GMC Sierra to shake while it is idling. Not only will you feel the shaking while idling, but you may also feel it when you place your truck in gear.
When the intake manifold, vacuum hose, gasket, or a vacuum-powered accessory is faulty or springs a leak, then the vacuum-controlled environment that is created within the engine of a GMC Sierra becomes unstable. An unstable engine vacuum system can cause the truck to shake when it is idling.
Bad fuel injectors
Bad fuel injectors will be unable to regulate how much fuel is entering the engine’s combustion chamber. There is a calculated perfect amount of fuel that needs to be mixed with air before entering the engine’s combustion chamber and too much or too little can cause the engine to run rough and shake while idling.
A clogged air filter can restrict airflow from getting to the engine and cause the engine to run rough and idle when shaking. You should be changing your engine air filter once every 12,000 miles or once a year.
My GMC Sierra shakes while it is accelerating
Some of the same reasons that your GMC Sierra shakes when it is idling can also be a cause of a GMC Sierra that shakes while it is accelerating. For example, if your truck is misfiring and idling roughly due to a bad spark plug, spark plug wires, or faulty ignition coil parks, you may experience similar shaking and misfiring while you are accelerating your vehicle.
Also, a bad motor mount is going to cause your vehicle to shake when it is idling and when it is accelerating. Let us take a look at some other issues that may be at the root that causes a GMC Sierra to shake when it is accelerating.
Bad inner CV joint
Although you may feel your vehicle shake and potentially hear weird noises at all different speeds if you have a bad inner CV joint, you are more likely to feel it intensely when you are accelerating hard or when you are turning and taking corners.
An inner CV joint replacement typically can cost anywhere from between $60 and $150 per joint and between $150 to $350 for labor. Although the replacement can seem expensive, if you do not go through with the inner CV joint replacement, you may cause your vehicle additional damage that will make the cost of repairs even higher.
If you start to notice excessive vehicle shaking when you are accelerating in your GMC Sierra, it could be an indication that your driveshaft is damaged or bent, or that the U-joint is wearing out. If you suspect this to be the case, then you may want to have your GMC technician or local mechanic inspect the driveshaft and universal joint for any visible damage or signs of wear that would cause either one to operate improperly.
If a piston in the brake caliper gets stuck or if the brake line becomes crimped, it may cause a GMC Sierra to shake more when it accelerates. Additionally, your vehicle may pull to one side or the other depending on which brake caliper is stuck.
Another sign of a stuck brake caliper is a burning smell coming from the affected wheel.
My GMC Sierra shakes at high speeds
If your GMC Sierra is shaking when you are driving at higher speeds on local highways or the freeway, then it may be a sign of unbalanced wheels, tire damage, bent rims, bad wheel bearings, loose lug nuts, or your entire vehicle steering alignment is off. As these are the most common issues, it could also be the result of a bad axle, worn-out suspension, or improper air pressure in the tires.
Unbalanced wheels may cause a steering wheel to shake if it is the front wheels that are out of balance and the body of the truck to shake if it is the rear wheels. There are several causes to wheels becoming unbalanced or it could be caused by not having your tires rotated properly and having your tires wear unevenly. It could be from violently striking potholes, curbs, or from off-roading.
Whenever you put on new tires onto your GMC Sierra or whenever you get your tires rotated, you should also ask to have your wheels balanced.
Alignment is off
If your alignment is off on your GMC Sierra, not only can your vehicle shake at higher speeds, but it may have a tendency to pull to the right or the left.
Alignments can become off slowly over time or from hitting potholes and curbs. Your alignment should also be inspected whenever you take your GMC in for a tire rotation. It is recommended that you get a tire rotation and alignment inspection once every six months or every 5,000 to 7,000 miles.
Tire and/or rim damage
If your GMC Sierra is shaking and vibrating at higher speeds, it could be an indication that your tires or rims are damaged. Inspect your tires to see if you find any noticeable damage like cuts, cracks, bulges, air bubbles, or if the tires are worn unevenly.
At the same time, check out the rims to look for any dents that may be significant enough to cause your vehicle to vibrate when driving at higher speeds. If you cannot detect any damage with the naked eye, you may want to have your tires and rims inspected by a professional tire shop that can use special tools to measure tread and find damaged areas.
Bad wheel bearing
If you hear grinding noises when driving and your vehicle shakes at higher speeds, it could be an indication that your wheel bearing is bad. The fast you drive, the louder the noise and the strong the shaking.
If your tires are not securely and properly attached to the wheel and the lug nuts are loose, this could cause your tires to wobble which would cause the entire truck to shake.
The faster you go the stronger the vibration will be. Always make sure to properly torque your lug nuts whenever you change a tire or double-check their tightness after taking your GMC Sierra in for a tire rotation.
Bad axle, suspension, or steering components
If your axle component is worn out, your suspension is too loose, or steering system components are not properly torqued, you could feel a strong vibration coming from the vehicle when traveling at high speeds. Additionally, if your ball joints or tied rods are worn out, they can throw off your vehicle alignment and cause your truck to shake and to pull to the right or the left.
Improper tire pressure
Having your tires filled with an improper amount of air can cause your vehicle to vibrate at higher speeds. Also, over-inflated tires can cause uneven wear of the tires by having only the center of the tire tread is in contact with the road instead of the entire tire.
My GMC Sierra shakes when slowing down
If your GMC Sierra is shaking and the steering wheel is vibrating as you are braking to slow down your vehicle, it could be a clear indication that your brake rotors are warped.
Warped rotors will need to be resurfaced or you will need to buy new ones. If your vehicle vibrates and you also hear a grinding noise coming from your car tires, then it could be a sign that your brake pads are completely worn. If you do not replace the pads immediately, it can lead to warped rotors.
Either way, if you are experiencing vehicle shaking when you are braking and slowing down your vehicle, you will want to see a brake specialist right away for a full inspection.