The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2019 LaCrosse rough idle and occasional stalling at stops

0

Melissa G. · rep 0 · May 22, 3:54 AM · 1 replies · solved · Question

Vehicle: 2019 Buick LaCrosse Premium

Hi everyone, I'm looking for some advice on my 2019 Buick LaCrosse Premium. For the past few weeks, I've noticed a really rough idle, especially when I'm stopped at a red light or in traffic. It feels like the car is shaking a bit more than usual, and the RPMs fluctuate slightly.

Even more concerning, it's stalled on me a couple of times when coming to a complete stop. It just completely dies, and I have to put it in park and restart it. It always starts right back up, but it's definitely not normal and a bit scary.

Any ideas what could be causing this in a 2019 LaCrosse? What should I be checking or telling my mechanic to look at? No check engine light yet, surprisingly.

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 3:54 AM

0

ClearTheCode admin answer:

Rough idle and occasional stalling in your 2019 Buick LaCrosse can be caused by a variety of factors, even without an immediate Check Engine Light. Here's a list of common culprits to investigate:

  1. Spark Plugs and Ignition Coils:

    • Cause: Worn spark plugs or failing ignition coils can lead to misfires, causing a rough idle and potential stalling. Even without a CEL, intermittent misfires can occur.
    • Action: Inspect spark plugs for wear. A diagnostic scan might reveal pending misfire codes (P0300 - Random/Multiple Cylinder Misfire Detected, or P030X for specific cylinders).

  2. Mass Air Flow (MAF) Sensor:

    • Cause: A dirty or faulty MAF sensor provides incorrect air intake readings to the engine control unit (ECU), leading to an improper air/fuel mixture, which can cause rough idle and stalling.
    • Action: The MAF sensor can sometimes be cleaned with specialized MAF cleaner. A failing MAF sensor might trigger codes like P0101 (MAF Sensor Performance).

  3. Throttle Body Issues:

    • Cause: Carbon buildup on the throttle body plate can restrict airflow at idle, leading to an inconsistent idle and stalling. Electronic throttle bodies can also malfunction.
    • Action: A mechanic can clean the throttle body. If it's an electronic issue, it might require replacement. Codes like P2101 (Throttle Actuator Control System Performance) could indicate a problem.

  4. Vacuum Leaks:

    • Cause: Leaks in vacuum lines or intake manifold gaskets can introduce unmetered air into the engine, disrupting the air/fuel ratio and causing a rough idle.
    • Action: A mechanic can perform a smoke test to identify vacuum leaks. This can sometimes lead to lean condition codes like P0171 (System Too Lean - Bank 1) or P0174 (System Too Lean - Bank 2).

  5. Fuel Delivery Problems:

    • Cause: Issues with the fuel pump, fuel filter, or fuel injectors can lead to insufficient fuel delivery, causing the engine to starve and stall.
    • Action: Check fuel pressure and inspect injectors. A clogged fuel filter is less common on newer vehicles but still possible.

When to See a Shop: Even without a CEL, the stalling issue is a safety concern. It's crucial to have your LaCrosse inspected by a qualified mechanic as soon as possible. They can perform a comprehensive diagnostic scan, including checking for pending codes, and physically inspect the components mentioned above to accurately diagnose and fix the problem.

Menu

Help & account