2017 Porsche 718 Boxster Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2017 Porsche 718 Boxster and How to Resolve Them

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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 2017 Porsche 718 Boxster 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 2017 Porsche 718 Boxster 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.

Brake caliper failure occurs in two different ways, and they create different symptoms.

The caliper can become stuck, in which case it won't release the brake pads. The seized caliper will cause the vehicle to brake constantly on one side, forcing the car to move toward that side. This pulling will be accompanied by a strong odor from one wheel.

Another way calipers fail is by leaking. If the caliper leaks, the brake pedal will feel too easy to push, and will sink all the way to the floor when held. Braking will become less effective the longer this goes on. There may also be brake fluid leaking onto the wheel.

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.

Brake rotors are mainly maintenance free, but when they have been subjected to abnormally hard use, the heat they absorb can cause the metal to turn blue, and cracking to occur. When this occurs, customers often specify they have lost braking power, or the vehicle's brakes are making noise. There may be no symptoms at all related to changing the brake rotors, since it is recommended to change brake rotors on most modern vehicles when performing a standard brake service.

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 initial diagnostic steps to take for a rough idle in a 2017 Porsche 718 Boxster?

When faced with a rough idle in your 2017 Porsche 718 Boxster, it's essential to adopt a methodical diagnostic approach to identify the root cause effectively. Start by checking for fault codes using a diagnostic scanner, as these codes can reveal specific issues within the vehicle's systems. Next, inspect the spark plugs; ensuring they are clean and functioning properly is crucial, as worn plugs can significantly impact engine performance. Don't overlook the air filter; a clogged filter can restrict airflow, leading to an uneven idle. Additionally, examine the vacuum lines for any leaks, as these can disrupt the air-fuel mixture and exacerbate idle problems. The throttle body should also be inspected for carbon buildup, which can hinder its operation; a thorough cleaning may restore proper function. Finally, assess the fuel system components, including the fuel pump and injectors, to ensure they are delivering the right amount of fuel. By following these steps, you can systematically diagnose and address the rough idle issue, potentially saving time and money on repairs.

What are the common causes of a rough idle in a 2017 Porsche 718 Boxster?

When diagnosing a rough idle in your 2017 Porsche 718 Boxster, it's crucial to consider several common problems that could be at play. One of the first areas to check is the air filter; if it's dirty or clogged, it can significantly restrict airflow to the engine, leading to performance issues. Additionally, inspect the spark plugs, as worn or faulty plugs can cause misfiring, which is a frequent culprit behind rough idling. Another potential issue is vacuum leaks, which can disrupt the air-fuel mixture and affect engine performance. Don't overlook the fuel system; a clogged fuel filter or malfunctioning fuel injectors can also contribute to an unstable idle. Furthermore, the mass airflow sensor plays a vital role in measuring incoming air, and if it's faulty, it can lead to incorrect air-fuel ratios. Lastly, issues within the ignition system, such as problems with ignition coils or wires, can also result in a rough idle. By systematically checking these components, you can identify and resolve the underlying issues affecting your vehicle's performance.

How urgent is it to address the rough idle in a 2017 Porsche 718 Boxster?

Addressing a rough idle in your 2017 Porsche 718 Boxster should be treated as a priority due to the potential risks associated with ignoring this symptom. A rough idle can indicate underlying engine problems that, if left unresolved, may escalate into more severe issues, leading to costly repairs and decreased vehicle performance. Additionally, neglecting this issue can result in reduced fuel efficiency, which not only impacts your wallet but also contributes to increased emissions. More critically, a rough idle could signal malfunctioning sensors, clogged fuel injectors, or ignition system failures, all of which can compromise the safety and reliability of your vehicle. By taking prompt action to diagnose and repair the rough idle, you can prevent further damage and ensure that your Porsche continues to perform at its best, ultimately preserving its longevity and your investment.

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2017 Porsche 718 Boxster Rough Idle: Causes & Repairs