2015 Land Rover Range Rover Sport Has Rough Idle

Resolve Rough Idle in 2015 Land Rover Range Rover Sport 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 2015 Land Rover Range Rover Sport 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 Land Rover Range Rover Sport 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 steps to diagnose a rough idle in a 2015 Land Rover Range Rover Sport?

To effectively diagnose a rough idle in a 2015 Land Rover Range Rover Sport, it’s essential to adopt a systematic diagnostic approach that begins with simpler checks before progressing to more complex issues. Start by inspecting for vacuum leaks, as these are a common culprit for rough idling. Look for any damaged or disconnected vacuum hoses that may be allowing excess air into the engine, which can lead to a lean fuel mixture. Next, utilize a scan tool to analyze the fuel trims; if they are significantly lean at idle, this may indicate a vacuum leak or other issues affecting the air-fuel mixture. Following this, examine the spark plugs for wear or damage, as faulty plugs can lead to misfires and contribute to rough idling. Additionally, check the fuel injectors for clogs, which can disrupt fuel delivery and exacerbate the problem. It’s also important to assess the intake manifold for leaks or blockages, as these can significantly impact engine performance. Don’t overlook the coolant temperature sensor and other critical sensors, as malfunctions here can lead to erratic engine behavior. If the check engine light is illuminated, retrieving error codes can provide valuable insights into specific issues. Finally, ensure that the vehicle has had a recent tune-up to rule out basic maintenance problems. By following this structured diagnostic approach, you can effectively identify and address the underlying causes of a rough idle in your Range Rover Sport.

What are the common causes of a rough idle in a 2015 Land Rover Range Rover Sport?

When experiencing a rough idle in a 2015 Land Rover Range Rover Sport, it's essential to consider several common problems that could be at play. One of the primary culprits is vacuum leaks, which can lead to a lean air-fuel mixture, resulting in erratic RPMs and misfires. Additionally, worn or dirty spark plugs can disrupt fuel ignition, causing micro-misfires that contribute to an unstable idle. Clogged fuel injectors are another frequent issue, as they can hinder proper fuel delivery, further exacerbating rough idling. The Mass Airflow Sensor (MAF) also plays a critical role; if it becomes dirty or damaged, it can miscalculate the air entering the engine, leading to performance issues. Other factors to consider include a loose or broken gas cap, which can affect fuel system pressure, and problems with the catalytic converter, which can cause the engine to run poorly. Additionally, a malfunctioning EGR valve or a failing intake Variable Cam Timing (VCT) actuator can disrupt engine operation, while a weak low-pressure fuel pump may also contribute to rough idling. Lastly, valve cover gasket issues can lead to misfires if raw material becomes trapped. By systematically inspecting these components, DIYers can effectively diagnose and address the rough idle issue in their vehicle.

How urgent is it to address the rough idle in a 2015 Land Rover Range Rover Sport?

Addressing a rough idle in your 2015 Land Rover Range Rover Sport is crucial for several reasons. First and foremost, a rough idle can indicate underlying mechanical issues that, if ignored, may escalate into more severe engine damage. Symptoms such as vacuum leaks or faulty spark plugs can lead to lean misfires, which not only compromise engine performance but can also result in costly repairs down the line. Additionally, a rough idling engine can create an unstable driving experience, increasing the risk of stalling or losing control, particularly in high-traffic situations. This unpredictability poses a significant safety risk for both the driver and other road users. Furthermore, neglecting this issue can lead to decreased fuel efficiency and higher emissions, impacting both your wallet and the environment. By addressing the rough idle promptly, you not only enhance your vehicle's performance and safety but also engage in preventive maintenance that ensures the longevity and reliability of your Range Rover Sport. Ignoring these symptoms can complicate future diagnostics and repairs, making it imperative to take action as soon as possible.

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