1999 Chevrolet Lumina Has Rough Idle

Resolve Rough Idle in Your 1999 Chevrolet Lumina for Smooth Performance

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Reviewed by
Bo Fader
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 1999 Chevrolet Lumina 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 1999 Chevrolet Lumina 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.

Customers with drum brake systems often specify they have lost braking power, or that the vehicle's brakes are making noise. This is because brake drums do not dissipate heat very well, so the heat from hard braking will cause stress fractures. These fractures make can make noise on the brake shoes as the drum revolves around the shoes. Lastly, the brake shoes may not be problematic, but may cause a grinding noise while stopping. This would indicate the shoes have no braking material left, and the brake shoes must be changed before the vehicle can be safely driven.

Learn more about brake shoe symptoms

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 steps to diagnose and fix a rough idle in a 1999 Chevrolet Lumina?

To effectively diagnose and fix a rough idle in your 1999 Chevrolet Lumina, begin with a diagnostic approach that prioritizes simplicity and efficiency. Start by scanning for error codes using an OBD-II scanner, as these codes can pinpoint specific engine issues that may be causing the rough idle. Once you have this information, perform an idle relearn procedure to ensure the Idle Air Control Valve (IACV) is correctly calibrated. Next, conduct a thorough visual inspection of the engine, looking for obvious signs of wear or damage, such as broken motor mounts or vacuum leaks, which can significantly impact engine performance. Pay attention to common failure points that might not trigger a check engine light, as these can often be overlooked. To enhance your understanding, consider watching diagnostic videos that detail common causes of rough idling, including issues with spark plugs, fuel injectors, and sensors. Finally, follow comprehensive step-by-step guides that address less obvious causes, such as contaminated fuel or electrical connection problems. By systematically working through these steps, you can effectively restore your Lumina's engine performance and ensure a smoother idle.

What are the common causes of a rough idle in a 1999 Chevrolet Lumina?

When diagnosing a rough idle in a 1999 Chevrolet Lumina, it's crucial to consider several common problems that may be at play. One of the first areas to inspect is the air filter; a dirty or clogged filter can significantly restrict airflow, leading to poor engine performance. Additionally, worn or faulty spark plugs are notorious for causing misfires, which can manifest as a rough idle. It's also important to check for vacuum leaks, as these can disrupt the delicate air-fuel mixture necessary for smooth engine operation. Fuel system issues, such as a clogged fuel filter or malfunctioning fuel injectors, can further exacerbate idle problems by affecting fuel delivery. Don't overlook the ignition system either; components like the ignition coil or distributor cap can fail and lead to erratic idling. Lastly, a malfunctioning mass airflow sensor can throw off the engine's performance, particularly at idle. By systematically addressing these potential issues, DIYers can effectively troubleshoot and resolve rough idle symptoms in their Lumina, ensuring a smoother driving experience.

How urgent is it to address the rough idle in a 1999 Chevrolet Lumina?

Addressing a rough idle in your 1999 Chevrolet Lumina is crucial for maintaining the vehicle's performance and longevity. A rough idle often signals underlying issues within the engine, such as problems with the fuel or ignition systems, which, if left unchecked, can lead to decreased fuel efficiency and poor overall performance. Moreover, neglecting this symptom may result in more severe engine damage over time, potentially leading to costly repairs that could have been avoided with timely attention. While a rough idle may not pose an immediate safety risk, it is essential to recognize that it can escalate into more significant problems if ignored. Regular maintenance and prompt action in addressing a rough idle not only enhance your vehicle's efficiency but also safeguard against future complications, ensuring that your Lumina continues to run smoothly for years to come.

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1999 Chevrolet Lumina Rough Idle: Causes & Repair Costs