2016 Buick Regal Has Rough Idle

Diagnosing Causes of Rough Idle in Your 2016 Buick Regal and Solutions for a Smoother Ride

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Reviewed by
Devin Cabugcal
Written by RepairPal Car Genius
Updated January 14, 2025
0%
21% chance it's the
Spark Plugs
0%
15% chance it's the
Ignition Coil
0%
64% chance it's
Something else
The most common reasons a 2016 Buick Regal has rough idle are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.
  • Spark Plugs: Worn or fouled spark plugs can lead to misfires, poor fuel economy, and difficulty starting the engine.
  • Ignition Coil: A faulty ignition coil can cause misfires, rough idling, and difficulty starting the engine due to inadequate spark delivery to the spark plugs.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2016 Buick Regal has rough idle?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

Here are a few common symptoms of worn-out brake pads:

  1. Low brake pad warning light is on: Not all vehicles are equipped with this system, but if yours is, this dashboard indicator light will likely be the first signal it’s time to replace your brake pads.
  2. Brakes start to squeal regularly: This is often one of the first signs of worn brake pads and is caused by a metallic piece built into brake pads for this exact purpose. This part contacts the brake rotor to make a squealing or whining noise when the pads are low.
  3. Brakes make loud grinding noise: If not addressed early enough, your brake pads may get so worn that the metal backing plate of the pad grinds against the metal rotor.
  4. Brake pads look thin: You may be able to visually check your brake pad thickness to determine if they need replacement.

Most often, a brake system inspection will just be a routine portion of manufacturer specified maintenance, and will be performed at mileage intervals. In those cases, there will likely be no symptoms. However, when a brake system makes a funny noise, causes vibration, is hard to use, will not slow the vehicle, prevents the vehicle from driving, makes the vehicle pull to one side, or leaks brake fluid, the vehicle will need a visit dedicated to the inspection of the brake system.

What are the steps to diagnose a rough idle in a 2016 Buick Regal?

When diagnosing a rough idle in a 2016 Buick Regal, it's essential to adopt a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Start by using an OBD-II scanner to check for any error codes, as these can quickly point you to potential issues within the vehicle's computer system. Next, inspect the spark plugs, as worn or fouled plugs are common culprits of rough idling; replacing any damaged ones can often resolve the problem. Following this, examine the air filter for cleanliness, since a clogged filter can restrict airflow and negatively impact engine performance. It's also crucial to assess the fuel system for any blockages, such as clogged fuel injectors or a dirty fuel filter, which can hinder fuel delivery. Additionally, inspect the vacuum hoses for cracks or leaks, as these can disrupt the air-fuel mixture and lead to idling issues. Cleaning the throttle body is another important step, as carbon buildup can affect its operation. Finally, consider performing a smoke test to identify any vacuum leaks in the intake system. By following this structured diagnostic approach, you can effectively pinpoint and address the causes of a rough idle in your Buick Regal.

What are the common causes of a rough idle in a 2016 Buick Regal?

When diagnosing a rough idle in a 2016 Buick Regal, it's essential to consider several common problems that could be affecting your vehicle's performance. One of the primary culprits is vacuum leaks, which can disrupt the air-to-fuel ratio, leading to an unstable idle. Additionally, worn or faulty spark plugs can cause engine misfires, further contributing to the roughness. The throttle body also plays a crucial role; if it malfunctions, it can significantly impact how the engine runs at idle. Ignition coil issues are another common concern, as bad coils can lead to hesitation and misfires. Furthermore, don't overlook the condition of the motor mounts; if they are damaged, they may cause noticeable shaking at idle. Cold start issues, such as those indicated by the P050D code, can also lead to rough idling, particularly when the engine is first started. Lastly, factors like dirty components, irregular ignition, and changes in air intake can exacerbate the problem. By systematically checking these areas, you can effectively troubleshoot and resolve the rough idle issue in your Buick Regal.

How urgent is it to address the rough idle in a 2016 Buick Regal?

Addressing a rough idle in your 2016 Buick Regal is not just a matter of comfort; it is crucial for the overall health of your vehicle. A rough idle can indicate serious underlying problems, such as issues with the fuel system, ignition components, or even engine wear. If left unattended, these problems can escalate, leading to more significant damage and costly repairs. Additionally, a rough idle often results in decreased fuel efficiency, which can impact your wallet over time. By prioritizing the resolution of this issue, you not only enhance your driving experience but also safeguard your vehicle's performance and longevity. Ignoring the symptoms could compromise safety and lead to a breakdown, making it essential to address a rough idle as soon as possible.

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2016 Buick Regal Rough Idle Causes & Solutions | RepairPal