2016 Chrysler 300 Has Rough Idle

Diagnosing Causes of Rough Idle in Your 2016 Chrysler 300 and Solutions for a Smoother Ride

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Reviewed by
Bo Fader
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 Chrysler 300 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 Chrysler 300 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.

Brake caliper failure occurs in two different ways, and they create different symptoms.

The caliper can become stuck, in which case it won't release the brake pads. The seized caliper will cause the vehicle to brake constantly on one side, forcing the car to move toward that side. This pulling will be accompanied by a strong odor from one wheel.

Another way calipers fail is by leaking. If the caliper leaks, the brake pedal will feel too easy to push, and will sink all the way to the floor when held. Braking will become less effective the longer this goes on. There may also be brake fluid leaking onto the wheel.

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.

Brake rotors are mainly maintenance free, but when they have been subjected to abnormally hard use, the heat they absorb can cause the metal to turn blue, and cracking to occur. When this occurs, customers often specify they have lost braking power, or the vehicle's brakes are making noise. There may be no symptoms at all related to changing the brake rotors, since it is recommended to change brake rotors on most modern vehicles when performing a standard brake service.

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 initial diagnostic steps to take for a rough idle in a 2016 Chrysler 300?

When faced with a rough idle in your 2016 Chrysler 300, it's essential to adopt a systematic diagnostic approach to identify and resolve the issue. Start by checking for fault codes using an OBD-II scanner, as these codes can reveal specific problems within the engine's systems. Next, inspect the spark plugs for wear or fouling, as these components play a crucial role in engine performance. A clean air filter is also vital; ensure it is free from clogs that could restrict airflow. Additionally, examine the vacuum hoses for any signs of damage or disconnection, as leaks can significantly impact engine operation. Testing the mass airflow sensor is another critical step, as a malfunctioning sensor can disrupt the air-fuel mixture, leading to rough idling. Finally, don't overlook the throttle body; a buildup of carbon or dirt can hinder airflow and contribute to the problem. By following these steps in order, you can effectively diagnose and address the rough idle issue, ensuring your Chrysler 300 runs smoothly.

What are the common problems that could cause a rough idle in a 2016 Chrysler 300?

When dealing with a rough idle in your 2016 Chrysler 300, it's essential to consider several common problems that could be at play. One of the primary culprits is dirty or faulty spark plugs, which can lead to engine misfiring and an uneven idle. Additionally, a clogged fuel filter may restrict fuel flow, further exacerbating the roughness. It's also crucial to check for vacuum leaks, as these can disrupt the air-fuel mixture necessary for smooth engine operation. A malfunctioning oxygen sensor can throw off the air-fuel ratio, contributing to idle issues as well. Furthermore, a dirty throttle body can impede airflow, while problems with the mass airflow sensor can affect the engine's performance by altering the air-fuel mixture. Addressing these issues promptly not only enhances your vehicle's performance but also helps prevent more significant damage down the line.

How urgent is it to address the rough idle in a 2016 Chrysler 300?

Addressing a rough idle in your 2016 Chrysler 300 is not just a matter of comfort; it is crucial for the vehicle's overall health and performance. A rough idle can indicate underlying issues such as problems with the fuel system, ignition system, or engine sensors, which, if left unchecked, may lead to more severe complications. Ignoring this symptom can result in decreased fuel efficiency and poor engine performance, ultimately risking significant damage that could be costly to repair. Moreover, a rough idle may escalate into more serious problems that compromise the safety and reliability of your vehicle. Therefore, it is essential to prioritize this issue and conduct regular maintenance or repairs promptly. By addressing a rough idle early on, you can ensure your Chrysler 300 runs smoothly and efficiently, safeguarding both your investment and your driving experience.

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