2015 Jeep Grand Cherokee Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2015 Jeep Grand Cherokee and How to Resolve Them

Find Repair Location
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 2015 Jeep Grand Cherokee 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 2015 Jeep Grand Cherokee 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 2015 Jeep Grand Cherokee?

To effectively diagnose a rough idle in your 2015 Jeep Grand Cherokee, start with the simplest solutions and progressively tackle more complex issues. Begin by using an OBD-II scanner to check for any error codes, as these can provide immediate insights into potential problems. Next, inspect the spark plugs; worn or damaged plugs can significantly affect engine performance and should be replaced if necessary. Following this, examine the air filter for clogs that may restrict airflow, and check vacuum hoses for any leaks that could disrupt the engine's air-fuel mixture. It's also crucial to assess the fuel system, including the fuel filter and injectors, to ensure proper fuel delivery. Additionally, inspect the idle air control valve and clean the throttle body to maintain optimal airflow. Lastly, check for any exhaust restrictions and test the mass airflow sensor to confirm it is accurately measuring airflow. By following this structured approach, you can systematically identify and resolve the issues causing the rough idle in your vehicle.

What are the common causes of a rough idle in a 2015 Jeep Grand Cherokee?

When dealing with a rough idle in your 2015 Jeep Grand Cherokee, it's essential to understand the common problems that could be at play. One of the primary culprits is a dirty or clogged air filter, which can significantly restrict airflow to the engine, leading to performance issues. Additionally, faulty spark plugs are notorious for causing misfires, which can manifest as a rough idle. Another potential issue is vacuum leaks; these can disrupt the delicate air-fuel mixture necessary for smooth engine operation. Fuel system problems, such as a clogged fuel filter or a malfunctioning fuel pump, can also contribute to an uneven idle. Furthermore, a faulty oxygen sensor may throw off the air-fuel ratio, exacerbating the rough idle condition. Lastly, don’t overlook the throttle body; carbon buildup or a malfunctioning throttle position sensor can lead to similar symptoms. By identifying and addressing these common issues, you can restore your Jeep's performance and enjoy a smoother driving experience. Regular maintenance and timely repairs are key to preventing these problems from escalating.

How urgent is it to address the rough idle in my 2015 Jeep Grand Cherokee?

Addressing a rough idle in your 2015 Jeep Grand Cherokee is not just a matter of comfort; it is crucial for the overall health and safety of your vehicle. Ignoring this symptom can lead to a cascade of problems, including decreased fuel efficiency and potential damage to vital engine components. A rough idle often signals underlying issues that, if left unresolved, may escalate into more serious mechanical failures, resulting in costly repairs. Moreover, a poorly running engine can compromise your vehicle's performance and safety, making it essential to act promptly. Regular maintenance and immediate attention to symptoms like rough idling can significantly extend the lifespan of your Jeep, ensuring a smoother ride and preventing future headaches. Therefore, if you notice your Grand Cherokee idling roughly, it is advisable to investigate and address the issue as soon as possible to avoid further complications.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.