2012 Lexus LS460 Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2012 Lexus LS460 and Solutions for a Smoother Ride

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Reviewed by
Aisha
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 2012 Lexus LS460 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 2012 Lexus LS460 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 initial diagnostic steps to take for a rough idle in a 2012 Lexus LS460?

When faced with a rough idle in your 2012 Lexus LS460, it's essential to adopt a systematic diagnostic approach to identify the root cause effectively. Start by checking for fault codes using an OBD-II scanner, as these codes can reveal specific issues within the engine's systems. Next, inspect the spark plugs; worn or fouled plugs can significantly impact engine performance and may need replacement. Don't overlook the air filter; a clogged filter restricts airflow, which can lead to rough idling. Additionally, examine the vacuum hoses for any signs of damage or disconnection, as leaks can disrupt engine operation. Testing the mass airflow sensor is also crucial, as a malfunctioning sensor can throw off the air-fuel mixture. Finally, take a look at the throttle body for any carbon buildup or dirt that could hinder its function; cleaning it can often restore smoother idling. By following these steps, you can effectively diagnose and address the rough idle issue in your Lexus, ensuring a smoother driving experience.

What are the common causes of a rough idle in a 2012 Lexus LS460?

When dealing with a rough idle in your 2012 Lexus LS460, it's crucial to understand the common problems that could be at play. One of the primary culprits is dirty or faulty spark plugs, which can lead to engine misfires and an uneven idle. Additionally, clogged fuel injectors can disrupt the necessary fuel-air mixture, exacerbating the roughness. Another potential issue is vacuum leaks, which can create an imbalance in the air-fuel mixture, further contributing to the problem. A malfunctioning oxygen sensor may also affect the air-fuel ratio, leading to rough idling. Furthermore, issues with the mass airflow sensor can hinder engine performance, while faulty ignition coils can cause misfiring, resulting in a rough idle. By identifying and addressing these common issues, you can restore your Lexus LS460 to smooth operation, making it a rewarding DIY project.

How urgent is it to address the rough idle in a 2012 Lexus LS460 to prevent potential engine damage or safety risks?

Addressing a rough idle in a 2012 Lexus LS460 is crucial for maintaining the vehicle's performance and safety. A rough idle often signals underlying engine problems, such as misfiring cylinders or fuel system issues, which can escalate into more severe damage if not promptly addressed. Ignoring these symptoms can lead to decreased fuel efficiency and compromised drivability, posing safety risks on the road. Additionally, a rough idle may indicate serious concerns like worn spark plugs or faulty sensors, which can worsen over time. Therefore, it is essential for DIY enthusiasts to diagnose and resolve rough idle issues quickly to avoid costly repairs and ensure the vehicle operates safely and efficiently.

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2012 Lexus LS460 Rough Idle: Causes & Repairs | RepairPal