Car has Rough Idle after an Oil Change

Why Is Your Car Running Rough After Oil Change?

As car owners, we want our vehicles to run smoothly and efficiently. 

Unfortunately, our vehicle may encounter performance difficulties even after routine maintenance procedures, such as an oil change. 

One of the most prevalent problems that automobile owners face is rough idle. Rough idling occurs when a vehicle’s engine runs sporadically or unevenly, causing it to shake or vibrate when stopped at idle. 

This problem can be caused by several circumstances, including issues with the engine, fuel system, or ignition system. If left addressed, a rough idle can result in lower fuel economy, decreased engine performance, and possibly damage. This blog will discuss some common causes of rough idle after an oil change and how to diagnose and fix them.

Why is My Car Running Rough After Oil Change?

Car Running Rough Idle After Oil Change

Various probable causes exist for a car’s rough idling after an oil change. One possible cause is overfilling the engine oil, leading to foaming and reduced lubrication. Another possible reason is a dirty air filter, which can restrict the airflow to the engine and cause rough idling. Loose or damaged spark plugs can also cause misfires and rough idling, as can a clogged fuel filter, resulting in a lean fuel mixture. 

All these reasons are explained in detail in the below paragraphs!

Engine oil overfilled

Visualize your car engine as a delicate ecosystem where everything must be perfectly balanced to operate efficiently. An overfilled engine increases the pressure inside the crankcase, hindering the engine’s proper functioning. 

The excess oil also contacts the crankshaft, creating a frothy mixture that the engine cannot distribute effectively. This frothy mixture leads to engine performance issues, overheating, and damage due to poor lubrication. You may observe blue smoke or oil leaks from the exhaust, increased oil consumption, and the illuminating check engine light, signaling an engine problem.

However, the solution is straightforward. To remedy the problem, you only need to drain some of the excess oil until the correct level is on the dipstick. Moreover, changing the air filter if it’s soaked in oil is a good idea since it might impair engine airflow. Maintaining the correct oil level in your engine is critical to keeping it running smoothly and prolonging its lifespan.

Wrong oil viscosity

The viscosity of oil, which measures its resistance to flow, plays a critical role in your engine’s performance. Using the incorrect viscosity can transform your smooth ride into a bumpy one, making choosing the correct type of oil vital.

If the oil is too thick, it can’t flow easily into the engine’s deeper and tighter spaces, resulting in poor lubrication and increased engine wear and tear. On the other hand, if the oil is too thin, it can break down quickly due to increased friction and heat, leading to potential engine damage.

Low oil pressure, increased oil consumption, annoying knocking noises, reduced fuel economy, and even a check engine light are all signs of using the wrong oil viscosity. To address this issue, it’s essential to drain the old oil and replace it with the correct type of oil for your car model and climate. Also, remember to change the oil filter if needed. Selecting the suitable oil viscosity can significantly affect your engine’s health and performance, so making an informed decision is crucial.

Using expired oil

Using expired oil can indeed cause various problems for your engine. Additionally, expired oil can also cause the following problems:

  • Sludge Formation: Over time, oil can break down and form sludge, clogging oil passages and preventing oil from reaching critical engine parts. Engine components may get dry as a result, increasing wear and possibly leading to failure.
  • Corrosion: When oil degrades, it can also become acidic, which can cause corrosion in the engine. Corrosion can damage engine parts and create leaks, leading to further problems.
  • Clogging: Expired oil can also form deposits that can clog oil passages and filters, which can restrict oil flow and cause engine parts to run dry.

Dirty fuel injector

bad and Dirty fuel injector cause Rough Idle after an Oil Change

Fuel injectors are essential to the effective running of your engine. They inject fuel into the engine at a specific angle and amount, ensuring that it runs smoothly and effectively. However, fuel injectors can get dirty over time from buildup or debris restricting fuel flow.

When fuel injectors become dirty, they can cause a rough idle by creating an imbalance in the engine’s air and fuel levels. This can also result in decreased fuel efficiency, poor performance, increased emissions, and misfires. If left addressed, dirty fuel injectors might lead to more severe engine issues.

An exhaust gas analyzer or a visual inspection can be used to diagnose dirty fuel injectors. An exhaust gas analyzer measures the emissions from the engine and can detect imbalances in the fuel mixture. A visual inspection involves examining the fuel injectors for signs of buildup or debris.

Dirty fuel injectors can be cleaned with routine maintenance or a cleaning additive. Routine maintenance involves removing the fuel injectors from the engine and cleaning them using a specialized cleaning solution. A cleaning additive can also be added to the fuel tank to clean the fuel injectors while driving. However, it’s essential to use a cleaning additive compatible with your engine and follow the manufacturer’s instructions carefully.

Other possible causes of rough idle after an oil change

While using expired or incorrect oil can be a common cause of rough idling after an oil change, other possible causes exist. Some other potential causes of rough idle include issues with spark plugs, vacuum leaks, and broken carburetors.

Spark plug problems are one probable reason for rough idle. If the spark plugs are not functioning correctly, the engine may not receive enough spark to ignite the gasoline properly. As a result, the engine may misfire or run rough. If you suspect spark plug problems, you must get them tested and replaced.

A vacuum leak is another probable reason for rough idle. A vacuum leak occurs when there is a crack or break in the vacuum lines, causing air to enter the engine that shouldn’t be there. A higher-than-usual RPM can identify rough idling due to a vacuum leak. Vacuum leaks can cause many symptoms, such as misfires and backfires, and high pitch noise from the engine.

Rough idling can also be caused by carburetor problems in older vehicles. Carburetors are in charge of mixing the gasoline and air in the engine, and if they don’t operate properly, the engine will run rough. Black exhaust smoke is a solid sign that your carburetor needs to be serviced.

Thus, while using expired or incorrect oil can cause rough idle, other possible causes exist. Spark plug issues, vacuum leaks, and broken carburetors can all cause rough idling, and it’s essential to diagnose and fix these issues promptly to prevent more severe engine problems.

FAQs About Car Driving Rough After Oil Change

Can Bad Oil Cause Rough Idle?

Yes, bad oil can cause rough idle. If the oil is dirty or contaminated, it can’t properly lubricate the engine, leading to increased friction and vibration. This can cause the engine to run rough, especially at idle.

Will Oil Change Fix Rough Idle?

An oil change may fix rough idle if the problem is caused by dirty or contaminated oil. However, if the rough idle is caused by another problem, such as a bad spark plug or a malfunctioning fuel injector, an oil change won’t fix the problem.

Can Too Much Oil Cause Rough Idle?

Yes, too much oil can cause rough idle. If the oil level is too high, it can cause the engine to misfire. This can lead to increased vibration and a rough idle.

Can Low Oil Cause Rough Idle?

Yes, low oil can cause a rough idle. When your engine oil is low, the engine’s components don’t get properly lubricated, which increases friction and vibration. This can manifest as a shaky or shuddering feeling in the engine compartment, and you might even see the engine physically rocking back and forth. If you notice a rough idle, it’s best to check your oil level right away and top it off if necessary. It’s also a good idea to get your oil changed regularly to avoid this problem in the first place.

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When you change the oil in your car, a rough idle can become a troublesome problem. This can be caused by contaminated oil, incorrect viscosity, low oil pressure, or a faulty oil filter. This can lead to shaking, vibration, or even stalling of the engine, which can cause further damage if not addressed promptly.

To avoid this issue, it is suggested to use high-quality oil, follow the manufacturer’s recommendations for oil type and viscosity, and regularly check the oil pressure and level. 

Using a reputable oil filter and replacing it with every oil change is also recommended. If a rough idle occurs, check the oil level and pressure, inspect the oil filter, and refill the engine with fresh oil if necessary. Seeking professional assistance may be necessary if the problem persists.

In conclusion, proper oil and filter selection, routine maintenance, and prompt attention to engine issues are crucial in preventing o

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