The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2022 QX50 VC-Turbo rough idle and occasional misfires

0

David L. · rep 0 · May 22, 5:04 AM · 1 replies · solved · Question

Vehicle: 2022 Infiniti QX50 Essential

My 2022 Infiniti QX50 Essential, with the VC-Turbo engine, has developed a rough idle recently. It's not constant, but sometimes when I'm stopped at a light, the engine feels like it's shaking more than usual. I also had the check engine light flash briefly a couple of times, but it went off quickly. I suspect it might be an intermittent misfire.

The car has about 30,000 miles on it. I'm concerned about potential long-term issues with the VC-Turbo technology.

Has anyone else experienced similar symptoms with their QX50? What was the fix?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 5:04 AM

0

ClearTheCode admin answer:

  1. Scan for Diagnostic Trouble Codes (DTCs): Even if the check engine light is intermittent, a pending code might be stored. Look for:

    • P030X (e.g., P0301 for Cylinder 1 Misfire, P0300 for Random/Multiple Cylinder Misfire)
    • P0420 (Catalyst System Efficiency Below Threshold - often related to misfires or rich/lean conditions)

  2. Common Causes for VC-Turbo Rough Idle/Misfires:

    • Spark Plugs: Worn or fouled spark plugs are a common cause of misfires. The VC-Turbo engine can be sensitive to plug condition.
    • Ignition Coils: A failing ignition coil can lead to intermittent misfires on a specific cylinder.
    • Fuel Injectors: Clogged or faulty fuel injectors can cause an improper air/fuel mixture, leading to rough idle and misfires.
    • Carbon Buildup: Direct injection engines like the VC-Turbo are prone to carbon buildup on intake valves, which can restrict airflow and cause misfires.
    • Variable Compression Mechanism Issues: While less common, issues with the complex variable compression system could potentially affect engine stability.
    • PCV System: A clogged or failing PCV valve can lead to oil consumption and affect engine vacuum, contributing to rough idle.

  3. When to See a Shop:

    • If the check engine light stays on or flashes frequently.
    • If the rough idle becomes constant or the engine stalls.
    • If you notice a significant drop in fuel economy or power.
    • An Infiniti dealership or a shop familiar with the VC-Turbo engine can perform advanced diagnostics, including compression tests, fuel system checks, and potentially scope inspections for carbon buildup. Prompt attention can prevent catalytic converter damage.
Menu

Help & account