2017 Cadillac XTS Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2017 Cadillac XTS and How to Resolve Them

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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 2017 Cadillac XTS 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 2017 Cadillac XTS 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 the rough idle issue in a 2017 Cadillac XTS?

When diagnosing a rough idle issue in a 2017 Cadillac XTS, 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 identify any error codes, as these can pinpoint specific problems within the vehicle'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 dirt and debris to maintain proper airflow. Additionally, examine the vacuum hoses for any signs of damage or leaks, as these can significantly affect engine idle. The fuel system should not be overlooked; check the fuel filter and injectors for clogs or dirt that could disrupt fuel delivery. Cleaning the throttle body is another important step, as carbon buildup can hinder its function. Finally, test the idle air control valve to confirm it is operating correctly. By following this structured diagnostic approach, you can effectively identify and resolve the rough idle issue in your Cadillac XTS.

What are the common problems that could cause a rough idle in a 2017 Cadillac XTS?

When dealing with a rough idle in your 2017 Cadillac XTS, it's essential to consider several common problems that could be affecting your vehicle's performance. One of the primary culprits is dirty or faulty spark plugs, which can cause misfiring and lead to an uneven idle. Additionally, clogged fuel injectors can disrupt the necessary fuel-air mixture, further contributing to the roughness. Another potential issue is vacuum leaks, which can significantly impact the air intake system, resulting in instability during idling. A faulty oxygen sensor may also be at fault, as it can alter the air-fuel mixture, leading to erratic engine behavior. Lastly, problems with the mass airflow sensor can interfere with the engine's air intake, exacerbating the rough idle. By identifying and addressing these common issues through regular maintenance and timely repairs, you can restore your Cadillac XTS to smooth operation.

How urgent is it to address the rough idle in a 2017 Cadillac XTS?

Addressing a rough idle in your 2017 Cadillac XTS is not just a matter of comfort; it is crucial for the vehicle's overall health and safety. A rough idle can signal underlying engine problems that, if ignored, may escalate into more severe issues, leading to costly repairs and decreased vehicle performance. Additionally, a rough idle often results in reduced fuel efficiency, which can impact your wallet over time. More critically, some causes of a rough idle may pose safety risks, such as engine stalling or erratic behavior while driving. Therefore, it is essential to diagnose and resolve the issue promptly. Regular maintenance and immediate attention to symptoms like a rough idle can help ensure your Cadillac XTS operates smoothly and reliably, safeguarding both your investment and your safety on the road.

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2017 Cadillac XTS Rough Idle Causes & Repairs | RepairPal