Car Shakes When Starting Then Runs Fine – Why It Happens

Car shakes when starting then runs fine may appear problematic, especially if you are experiencing it for the first time. You sure want your vehicle to be in optimum condition, and the unnecessary vibration you feel upon ignition signals something is wrong.

However, it could be a minor issue that a quick fix can rectify. This article discusses the potential causes of this issue and its solutions.

What Causes Your Car To Shake When You Start It?

What causes your car to shake when you start it is issues with the engine. Also, it could be a slight problem, such as having a loose engine part, which triggers vibration when you put on the ignition. Issues with alignment, brakes, or car tires may also be the cause.
Below is a more detailed review of possible reasons why your car vibrates when you start.

• Faults With the Engine

A faulty engine is a recipe for many car problems. The issue arises from the engine not receiving enough air, fuel, or an inefficient air-fuel mixture. Also, there could be issues with spark plugs or clogged fuel filters, which would alter some engine functionalities.

Another possible engine-related fault that could cause the car to shake upon ignition is issues with the crankshaft damper. In fact, this harmonic balancer is a critical factor. One of its primary functions is to prevent engine shaking. Therefore, when faulty, your car is bound to vibrate rigorously.

• Loose Engine Components

If some engine parts, such as the belt or pulleys, are loose, they can cause some vibrations when you kickstart your car. And, as the engine runs for a while, loose components may settle into their normal position. This kills off the initial vibration noticed. If otherwise, the car continues to vibrate around the area with the loose parts.

• Issues With Car Tires

Issues with your tires alone may not be enough to precipitate the shaking you notice upon starting the engine. However, they may act as contributing factors to the vibrations you perceive. They are often associated with imbalance or alignment issues. Damaged tires, worn-out tire threads, deflating tires, misaligned tires, etc., are more likely to cause such vibrations.

• Faulty Brakes

Issues with the car braking system, such as warped brake rotors, may cause the car to vibrate upon engine ignition. This issue may result from wear and tear, causing the rotor to get out of shape or even flatten. This causes the car to shake when you start it.

• Misfiring Engine

This is when one or more engine cylinders are not optimally igniting the air-fuel mixture, resulting in misfiring. When this happens, it causes the car to vibrate, especially upon ignition. The check engine light, too, will illuminate.

Typical causes for the engine to misfire include faults with the ignition coils, engine sensors, or faulty spark plugs.

• Faulty Motor Mounts

Issues with the motor mount are another main reason that can cause your car to vibrate. One of the functions of the engine mount is to absorb the gearbox vibrations and movement as the vehicle operates. Therefore, a bad motor mount may result in the excessive trembling of the car.

• Bad Spark Plug

The spark plug typically creates the electric spark that ignites the air-fuel mixture, stimulating combustion in the internal combustion chamber. Issues with your car’s spark plugs can cause your car to misfire and experience vibrations.

• Issues With the Fuel System

The car fueling system is another integral component required for optimum car functioning. For example, clogged fuel injectors would affect fuel delivery, which may potentiate vibrations. Also, low fuel pressure may cause the car to shake upon switching on the ignition, or if the vehicle is running lean, that is, a lean air-fuel mixture.

• Other Loose Car Components

Besides loose engine parts, other car parts, when not correctly attached or fitted in place, may cause excessive shaking causing the car to shake. Such loose components could range from rattling heat shields and tension pulleys to exhaust systems.

What Are the Solutions to Your Car Shaking When Starting?

The solutions to your car shaking when starting revolve around addressing the cause. For example, if it is caused by loose engine or car components, the solution is to tighten the loose part. Afterward, you shouldn’t experience that unnecessary vibration when you start the car.

Therefore, we will be exploring the solutions to the different causes of your car vibration when starting in detail.

• Tighten Loose Engine Components

Knowing that loose engine parts can cause your car to make unnecessary vibrations, tightening these loose parts can help stop them. When you suspect that the shaking parts of your vehicle are a loose engine component, ensure your car is packed, then pop the hood to locate the loose part.

Ensure to use appropriate tools, such as a wrench or a screwdriver, tighten the loose boots or screws, and ensure they are properly sealed. You can then restart your car and keep it idling for a few minutes to see if the vibrations have stopped. If otherwise, repeat the steps. If it persists, then the vibration source is probably not a loose part.

• Replace Faulty Motor Mounts

To replace bad motor mounts, ensure your car is turned off, including the headlights and other accessories. Next, pop the hood to lo cage the motor mounts. Afterward, disconnect the electrical connections linked to the mount. Use a wrench or any other suitable tool to remove the bolts that attach the mounts to the engine.

Now, you can install the new engine mounts instead of the defective one. Remember to reconnect the electrical components and ensure you do everything correctly. Then you can close the hood, and restart your car, paying attention to notice if the vibrations have stopped. If not, repeat the process.

• Inspect and Rebalance Car Tires

Since issues with car tires too may cause your car to shake, inspecting the tires is necessary, especially if you are yet to detect the cause. Ensure to park your vehicle correctly on a level surface. The next thing is to jack up your car but ensure it is well supported to prevent your vehicle from collapsing when it’s raised.

Now, remove the wheels and place them on an appropriate balancing machine. Carefully read the balance instruction manual, and adhere to it as you attempt to realign your wheels. Do this for the other three wheels. Afterward, you’d notice that your car is well-balanced. The next thing is to take your car for a test drive to ensure the problem is rectified.

This fix solves the car tire issues and corrects alignment problems that may cause the car to tremble. However, it is quite tasking, so consider consulting with an expert to rectify the situation.

• Tighten Loose Body Parts

As we mentioned earlier, your car may experience unnecessary vibrations beyond loose engine components if the body parts are not tightly fitted. When you start your car and notice the vibration, you can keep it idling to observe any loose body parts quickly. Immediately you spot the loose part, switch off your ignition.

Get the appropriate tool, a socket and ratchet, or a wrench to tighten the loose bolt or screw. Afterward, you can restart your car. You shouldn’t notice any shaking if you tighten the open part properly.

• Fix Engine Faults

Beyond loose engine parts, we mentioned earlier that faults with specific engine components may also cause your car to vibrate. Fixing the particular engine defect will help numb the trembling noise. This may include replacing worn-out spark plugs, and cleaning or replacing dirty air filters, among other engine parts.

It is quite tasking to detect a particular engine fault, considering your engine consists of several parts. Therefore, we recommend consulting with an expert when you notice the vibration from the engine. You could request a general car servicing, emphasizing the main issue. However, if you like to get your hands dirty, you can explore your car’s engine and diagnose and fix the problem.

FAQs

– How Can You Prevent Your Car From Shaking During Startup?

You can prevent your car from shaking during startup by following simple car maintenance and preventive measures. Ensure routine servicing of your vehicles, and inspect each part of your car regularly to ensure tight fittings. Visit an auto repair center whenever you notice any changes in your car’s functionality.

– Can Cold Weather Cause Your Car to Shake Upon Ignition?

Yes, cold weather can cause your car to shake upon ignition. The cold weather can cause the fluids in your vehicle, fuel and oil, to thicken. This causes increased viscosity, friction and resistance in fluid flow, resulting in more vibrations till the oil heats up for proper functioning.

– How Do Your Car Body Parts Get Loose?

Your car body parts get loose after extended use. As your car ages and you use them from time to time, after a while, different parts begin to expand at different rates causing fitted components to loosen. Also, off-road driving can increase the rate at which car parts loosen.

Regular driving in rugged and rough terrains stresses your car and may also increase the rate at which your body parts loosen. Most car parts are secured with fasteners, welds, adhesives, etc. So, any of these parts can get loose and then your car shakes for a few seconds when you start it.

 

Conclusion

Having read this article thus far, you probably understand the possible causes of your car vibrating upon ignition and the solution. That said, let’s make a brief overview of all that we’ve discussed thus far.

• Your car shakes when you put on the ignition because of an issue with the engine, such as a loose engine component, dirty filters, bad spark plugs, etc.
• Other potential causes of your car trembling include loose components, broken motor mounts, issues with car tires, misalignment, etc.
• The solution to your car shaking involves identifying and rectifying the cause of the vibration. This includes fixing and tightening engine components, rebalancing or along the wheels, etc.
• Cold weather or temperature may cause your car to vibrate, as it causes the oil or fuel to thicken, increasing viscosity and resistance.
• Over time, your car parts, including the tires, may wear out and become loose, especially if you regularly drive in rough terrains. Therefore, routine off-road driving may potentiate your car vibrations.

If you cannot spot the cause of the vibrations, you should avoid trial and error to prevent tampering with critical car components. Instead, visit an auto shop, where an expert can diagnose and rectify the car issue.