1999 Chevrolet Cavalier Has Rough Idle

Resolve Rough Idle in 1999 Chevrolet Cavalier for Smooth Performance

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Reviewed by
Andrew Hajjar
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 Cavalier 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 Cavalier 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 a rough idle in a 1999 Chevrolet Cavalier?

To effectively diagnose a rough idle in a 1999 Chevrolet Cavalier, it is essential to adopt a systematic diagnostic approach that begins with simpler checks before progressing to more complex issues. Start by inspecting for vacuum leaks, as these can significantly affect engine performance; look for any cracks or disconnections in the vacuum hoses. Next, examine the spark plugs, replacing any that appear worn or dirty, since they are vital for proper combustion. A clogged air filter can disrupt the air-fuel mixture, so ensure it is clean and replace it if necessary. Following this, test the fuel pressure with a gauge to confirm it meets the manufacturer's specifications, as inadequate fuel delivery can lead to rough idling. The Idle Air Control Valve (IAC) is another critical component; check its functionality and clean or replace it if it shows signs of wear. Additionally, cleaning the throttle body can help eliminate carbon buildup that may affect idle quality. To further pinpoint issues, use an OBD-II scanner to check for any error codes that could indicate specific problems. Lastly, inspect the EGR valve, as a malfunctioning or clogged valve can also contribute to rough idling. By following this structured diagnostic approach, you can effectively identify and resolve the underlying causes of a rough idle in your Cavalier.

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

When dealing with a rough idle in your 1999 Chevrolet Cavalier, it's essential to understand the common problems that could be at play. One of the first areas to check is the air filter; a dirty or clogged filter can significantly restrict airflow, leading to performance issues. If the air filter appears dirty, replacing it is a straightforward DIY task that can improve engine efficiency. Next, inspect the spark plugs; worn or faulty plugs can cause misfiring, which directly affects idle quality. Replacing spark plugs is a manageable job for most DIY enthusiasts. Additionally, vacuum leaks can disrupt the air-fuel mixture, so examining hoses for cracks or disconnections is crucial. If you suspect fuel system issues, such as a clogged fuel filter or a malfunctioning fuel pump, these components may require more advanced troubleshooting or replacement. The Idle Air Control Valve (IACV) is another critical component; if it’s malfunctioning, it can lead to erratic idling. Cleaning or replacing the IACV can often resolve this issue. Lastly, don’t overlook the ignition system; problems with ignition coils or the distributor can also contribute to a rough idle. By systematically addressing these common causes, you can effectively troubleshoot and resolve the rough idle in your Cavalier, ensuring a smoother driving experience.

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

Addressing a rough idle in your 1999 Chevrolet Cavalier is not just a matter of comfort; it is crucial for the vehicle's overall health and performance. A rough idle can indicate underlying issues such as fuel system malfunctions, ignition problems, or sensor failures, which, if left unattended, may escalate into more severe engine damage. Ignoring this symptom can lead to decreased fuel efficiency and poor vehicle performance, ultimately costing you more in repairs down the line. Moreover, a rough idle can sometimes signal serious problems that could compromise your safety on the road. Therefore, it is essential to diagnose and resolve the issue promptly. Regular maintenance and timely repairs not only enhance your vehicle's reliability but also extend its lifespan, making it a wise investment for any DIY enthusiast looking to keep their Cavalier running smoothly.

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