A car that shakes at idle but smooths out while driving is a problem. There are many reasons why your car might shake while idling. Here, we will discuss some of the common causes of this issue and how to fix them yourself.
What Does It Mean When Your Car Vibrates?
Vibration describes the motion that occurs within an object, such as a motor vehicle. In this context, vibration refers to the physical sensation felt by passengers in a vehicle moving over road surfaces with different patterns and surfaces. For example, if you are driving on bumpy asphalt with smooth concrete beneath it, your car will feel like it is shaking or bouncing around while you drive over surfaces like this.
What Can Cause and How To Fix A Car That Shake At Idle But Smooths Out While Driving?
The following are the common causes of why your car may shake at idle:
1. Idle Speed control
The first thing you should do is check the idle speed control switch. It’s located in your engine compartment, usually on top of the air cleaner assembly. If it’s defective, replace it with a new one. If this doesn’t solve your problem, there may be something wrong with your idle speed control valve or motor.
HOW TO FIX IT: You’ll need to remove these components to inspect them and ensure they’re working properly before replacing them if they’re damaged or malfunctioning.
2. Damaged Spark Plugs
If your car shakes at idle but runs smoothly while driving, it could be due to an issue with the spark plug. The spark plug is a small piece of metal responsible for igniting your engine’s fuel, so it’s easily one of the essential parts of a machine.
The first step in diagnosing this problem is to check whether or not all four spark plugs are correctly seated in their respective holes on the cylinder head. If they aren’t all snugly inserted into place, you’ll need to either remove and reinstall each spark plug or replace them all (depending on how many are missing).
HOW TO FIX IT: First, remove them from their sockets (don’t forget about grounding straps.). Then use compressed air to blow away any dirt or grime clinging stubbornly onto each tip; be careful not to damage any nearby wires while doing so. Once they’re cleanly wiped down, reinstall them carefully back into their respective sockets (again, taking care not to bend wires).
3. Bad car alternator
A bad alternator can cause your car to shake at idle. The alternator is responsible for charging the battery, which provides power to the electrics in your vehicle. If you’re unsure whether your car’s problem is related to a faulty alternator, check its voltage regulator first. This part regulates the flow of current from the battery to the rest of your vehicle’s electrical components so that they receive enough power but don’t waste too much energy on unnecessary functions like lights and heating systems if they aren’t needed at any given moment.
Suppose you have an OBD2 scan tool that can read codes stored by sensors within your engine bay (such as those listed above). In that case, it could save you time and money by alerting you when there are issues with individual components rather than simply assuming that every single one needs replacing without doing any diagnostic work first.
4. Clogged Fuel Intake System
When troubleshooting your car’s fuel system, it’s important to remember that the fuel filter is a crucial component. If the filter is clogged with debris or sediment, fuel can’t get through it, and you’ll experience some of the symptoms mentioned above.
HOW TO FIX IT: To check your gas filter, look at its housing. Often this will be labeled with “fuel” or “filter.” If there are two caps on opposite sides of this housing, remove them and note how they were attached: some may use screws, while others may pry off by hand. Pull out any old filters inside by hand if necessary; they’re usually located at one end of their respective housings (the other end should contain an additional cap). Make sure that all components are removed before installing new ones.
If replacing your old filter doesn’t solve these issues with shaking at idle speeds but smooths out once driving begins again, then it would seem reasonable to assume that there might be something wrong with either the pressure regulator or lines themselves taking fluid from tank(s) into engine cylinders for combustion purposes.
5. Faulty Motor Mounts
Loose or broken motor mounts can cause your car to shake at idle. If the car shakes while idling but smoothes out while driving, it may be because of a faulty or loose motor mount. A loose mount allows for more vibration from the engine, which will cause it to shake in its place as it tries to absorb that extra force by moving back and forth along with the vibrations.
HOW TO FIX IT: To replace motor mounts, start by removing them one by one, so you can put new ones in their place on a clean surface like a garage floor. After installing each new mount, test drive your vehicle to see if any issues have been fixed.
6. Loose engine mounts
If you notice your car shaking while idle but smoothing out as you drive, your engine may be loose. The engine mounts are responsible for this. They hold the engine in place so it can’t shift around while driving.
There are different engine mounts: rubber and polyurethane (both types can be used on older cars) and metal (mostly on newer models). Engine mounts are bolted to the frame and the engine with bolts stretching through bushings (rubber or polyurethane). If these bolts loosen over time or if their bushings break down due to age or other factors, this could cause an issue with shifting.
HOW TO FIX IT: One way to check whether your motor mount needs replacing is by feeling around underneath where the oil filter sits. If there’s any movement between these two parts, then there may be an issue with one falling out of alignment or being broken altogether.
FREQUENTLY ASKED QUESTIONS
Is it Safe to Drive a Car with a Rough Idle?
If your car engine is shaking at idle but smoothes out while driving, you should be able to drive your car with no problems. However, suppose a major problem with your car engine is causing an abnormal amount of shaking at idle but smoothes out while driving, it may be best to have it inspected by a qualified automotive technician.
The most common symptom associated with an abnormal amount of shaking at idle is when you drive over 50 mph on level ground without any turns in either direction for about 15 minutes or so. Suppose this happens frequently enough to cause concern for safety reasons or fear of injury from riding around in an unsafe vehicle. In that case, we recommend having auto mechanics inspect your vehicle immediately.
Why Does My Car Shake After I Change The Spark Plugs?
When you change your spark plugs, the engine will shake at idle. You can fix this by adjusting your idle speed or replacing them with another set of identical plugs. If neither of these options works for you, then something else could be causing the problem, such as bad fuel injectors or worn-out valves.
Read: Car Revving in Park
Conclusion
Car shaking at idles is a common problem associated with cars. This can also be caused by bouncing or rumbling sounds underneath your car. But these are the common factors that might make your car shake at idles, loose engine mounts, clogged fuel injectors, bad car alternators, faulty motor mounts, faulty idle control, and damaged spark plugs.