2008 INFINITI G35 Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2008 INFINITI G35 and How to Resolve Them

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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 2008 INFINITI G35 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 2008 INFINITI G35 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 2008 INFINITI G35?

When addressing a rough idle in your 2008 INFINITI G35, it's essential to adopt a systematic diagnostic approach that prioritizes simpler checks before delving into more complex issues. Start by inspecting for vacuum leaks, as these can significantly disrupt the air-fuel mixture, leading to an unstable idle. Next, examine the air filter; a dirty or clogged filter can restrict airflow, exacerbating the problem. Following this, assess the condition of the spark plugs, as worn or fouled plugs can cause misfires that contribute to rough idling. Utilizing an OBD-II scanner to check for error codes can provide valuable insights into any underlying issues, such as sensor malfunctions or misfires. Additionally, ensure that the fuel system is functioning correctly by checking the fuel injectors for clogs or faults, as these can also lead to idle irregularities. Finally, inspect the throttle body for cleanliness and proper operation, as a malfunctioning throttle body can disrupt airflow and worsen the idle. By methodically working through these steps, you can effectively identify and address the root causes of a rough idle in your vehicle.

What are the common problems that could cause a rough idle in a 2008 INFINITI G35?

When dealing with a rough idle in your 2008 INFINITI G35, it's essential to consider several common problems that could be affecting your vehicle's performance. One of the primary culprits is a dirty or faulty mass airflow sensor, which can disrupt the delicate balance of air and fuel entering the engine, leading to an unstable idle. Additionally, vacuum leaks can create an improper air-fuel mixture, exacerbating the rough idle issue. It's also crucial to inspect the spark plugs and ignition coils, as worn components can cause misfires that contribute to an uneven idle. A clogged fuel filter may restrict fuel flow, further impacting engine performance at idle. Furthermore, issues with the idle air control valve can disrupt the engine's idle speed, while carbon buildup or malfunctions in the throttle body can hinder air intake. By systematically checking these components, you can effectively diagnose and address the rough idle problem, ensuring your G35 runs smoothly.

How urgent is it to address the rough idle in my 2008 INFINITI G35?

Addressing a rough idle in your 2008 INFINITI G35 is crucial for maintaining the vehicle's performance and longevity. Ignoring this symptom can lead to a cascade of issues, including decreased fuel efficiency and potential engine misfires, which may escalate into more severe damage over time. Common culprits behind a rough idle include dirty fuel injectors, clogged air filters, malfunctioning oxygen sensors, and faulty spark plugs. For DIY enthusiasts, it’s essential to regularly inspect these components and perform maintenance tasks such as cleaning or replacing filters and spark plugs. By taking proactive measures, you can not only enhance your vehicle's performance but also avoid costly repairs down the line. If the problem persists despite your efforts, consulting a professional mechanic is advisable to ensure that any underlying issues are accurately diagnosed and resolved.

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2008 INFINITI G35 Rough Idle Causes & Repair Costs