The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2017 Q60 3.0t Rough Idle and Misfire - Spark Plugs?

0

Brittany E. · rep 0 · May 22, 5:08 AM · 1 replies · solved · Question

Vehicle: 2017 Infiniti Q60 3.0t Premium

Hello Infiniti community,

I'm having some issues with my 2017 Infiniti Q60 3.0t Premium. Lately, it's developed a rough idle, and I can feel it misfiring sometimes, especially when accelerating. The check engine light came on, and when I scanned it, I got P0301 and P0303 codes, indicating misfires in cylinders 1 and 3.

The car has about 75,000 miles on it. Could this be as simple as needing new spark plugs? What's the recommended interval for spark plug replacement on the VR30DDTT engine? Any tips for DIY replacement?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 5:08 AM

0

ClearTheCode admin answer:

Experiencing a rough idle and misfires with P0301 and P0303 codes on your 2017 Infiniti Q60 3.0t at 75,000 miles strongly suggests that spark plugs are a very likely culprit. The VR30DDTT engine is known to benefit significantly from timely spark plug replacement.

  1. Spark Plug Interval: For the VR30DDTT engine, Infiniti generally recommends spark plug replacement every 60,000 miles under normal driving conditions. At 75,000 miles, you are past this interval, making worn spark plugs a prime suspect for your misfire codes.
  2. OBD Codes Explained:
    • P0301: Cylinder 1 Misfire Detected
    • P0303: Cylinder 3 Misfire Detected These codes indicate that the engine's computer detected a misfire in those specific cylinders, meaning the combustion process wasn't optimal.
  3. DIY Spark Plug Replacement (General Steps):
    • Gather Tools: You'll need a spark plug socket (typically 14mm thin-wall for the VR30), various extensions, a ratchet, torque wrench, dielectric grease, and anti-seize (optional, check plug manufacturer recommendations).
    • Access: The VR30DDTT engine requires removal of the engine cover and potentially some intake components to access the coil packs and spark plugs, especially on the driver's side (cylinders 1, 3, 5).
    • Procedure: Disconnect the battery. Carefully remove the ignition coils (one per cylinder). Use compressed air to blow out any debris around the spark plug before removal. Unscrew the old plugs. Apply a small amount of dielectric grease to the inside of the new coil boots and anti-seize to the spark plug threads (if recommended). Install new spark plugs, hand-tightening first, then torque to the manufacturer's specification (typically around 14-18 ft-lbs for these plugs). Reinstall coil packs and other components.
  4. When to See a Shop:
    • If replacing the spark plugs doesn't resolve the issue, the problem could be related to ignition coils, fuel injectors, or even compression issues in those cylinders. A shop can perform further diagnostics.
    • If you're uncomfortable with the process, especially torquing the plugs correctly to avoid damage to the cylinder head threads.
Menu

Help & account